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Bundy
08-17-2005, 09:09 PM
Hi

Has anyone done any work with adding real engine sounds to their electric warbird? I'm currently flying a 101" B-25 powered by 2 AXI 5330/18 turning 18 x 10 APC-E props. These make a beautiful , subtle sound but one of the local 'petrol heads' here said "but it doesn't sound like the real one!" Neither do a pair single cylinder, 2 stroke chain-saw motors.

I remember seeing an article in Scale International mag where real engine sound was sampled and played back thru a speaker in the plane. I am about to start a Brian Taylor 82" Corsair and my plan is to put a 100mm, car stero sub-woofer in the firwall driven by a 50 watt amplifier and the 10S4P flight battery with the sound coming from a small MP3 player altho this site http://benedini.de/ENG/index.HTM offers more features at a price.

The main problem I think will be finding a speaker light enough with a the frequency range and power handling. The prototype Corsair was about 14/15lb, a speaker I've seen was around 1 lb so with the electric conversion I'm planning on an AUW of about 18-20lb. AXI 5330 on a 18" prop and 10S4P is producing around 2100watts which should be enough power to weight.

Any thoughts?

Richard
Bundaberg, Australia

Johnr
08-19-2005, 10:42 AM
Hi Bundy,
Never mind those petrol heads, they will all be ducking when you get them in a growling low straffing pass with your Corsair!:D

Pete pionted out this thread to me and maybe I can help a little.

Yes, you can do it, and the main problem is to find the right power speaker for the weight. I did the RCSI article and there will be a new article probably coming in QEFI in the October magazine. My HE111 with the sound crashed last September, and it had to be completely rebuilt. I am now sure that the problem was not the sound circuit and it has been working well all season. The Visaton 4" speaker that I use weighs about 6 ozs and two are used on the HE111. They are capable of about 20 watts each. The entire system weighs about one lb, so your hunt for a better speaker is the right one. Having said that, after trying lots of other speakers, I ended up using the speaker that Thomas Benedini said I should use!

Tell me more about the 5330 motors, how are you getting on with them and what rpm and current do you get? What is the weight of your B25 and what batteries are you using? We are looking at using those motors and it will be interesting to swap information.

All the best,

John

modeldesigns
08-19-2005, 01:21 PM
Hi Richard,

John is FAR too modest. To the best of my knowledge, John is the first person in the UK to have fitted a simulated engine sounding device to an electric scale model and he has the 'know-how'!. His Heinkel is performing better than ever since its rebuild and is now flying on brushless motors. It also posses cannon and machine gun sound simulation...and can deploy a Doodle Bug! An amazing modelleing achievment.

The pic was taken at the North London Baldock Club Scale Day this year. Johns latest is a Brian taylor based Me109 and the other three warbirds are my own Hanger 9 E conversions. I count six 4130/16 motors!

We both want to venture to larger machines, so your findings on the Axi 53 series would be most helpful.

Good luck with the Corsair,

Pete.

John Seidelman
08-20-2005, 02:18 AM
I just heard something on one of the science channels today about making a speaker out of any surface. I guess I should have watched it now. Maybe I will catch it this weekend and let you know.

John Seidelman
08-20-2005, 03:56 PM
I just heard something on one of the science channels today about making a speaker out of any surface. I guess I should have watched it now. Maybe I will catch it this weekend and let you know.

Just found the link
http://electronics.howstuffworks.com/framed.htm?parent=ces2004.htm&url=http://www.s3isound.com/
It was at the Sceince Channel on Sat. Looks cool, but I don't know if it will help or not.

Bundy
08-20-2005, 11:39 PM
Hi Guys

And thanks for inputs - some very nice looking planes there and electric!

My B-25 is built from the 101" Ziroli plan, weights in at 35lb ready to roll and the 2 AXI turning 18 x 10 APC-E really is too much power. Each AXI is powered from Thunderpower Prolites 10S4P (2 packs of 5S4P). At full bore this shows 2300watts on the wattmeter at 70 amps and 6900 rpm. I'm thinking 17" or even 16" props would be much kinder on the Future 55/73 ESC and still have enough power to fly effortlessly. As it is these motors will pull the 35lb round some beatiful big loops but I am pushing the limlts of the ESCs.

I orginally had a pair of Plettenberg 370/50 A3 in there but one of them threw a magnet on the maiden flight and siezed up. I had been using one of these motors in a 1/4 scale Tiger for nearly 2 years before this and really can't explain what happened. Neither can Plettenberg and weren't really too interested in finding out hence the change to AXI.

So far I'm more than happy with the AXI. They are far less noisy than the Plettenberg which tend to have a harsh, 'tight' whine to them. Two suppliers have hinted that the AXI perhaps don't have the build quality that some others might have and I suppose only time will tell. I'll be sure to keep you posted.

I've got a little more work to do on an electric 65" Mustang which I'm decking out with opening canopy, air vent and retracable tailwheel as a bit of a trial for some ideas for the Corsair. The idea of using a solid surface as a speaker is fascinating and will look into more to see if it has any appication to what we are doing.

Be sure to keep us posted on your building efforts and I will be looking out for the October mag.

Richard

luc
08-21-2005, 09:59 AM
I am surprised by the watts you mentioned, axi talks about 1900 watts "only" with a 19*12, far bigger than your 18*10...
I use also several axi (4130/16) on my planes (8lbs only) and found that these motors don't like too much high amps (I threw a magnet), so don't overcharge them

Bundy
08-21-2005, 10:53 AM
Hi Luc

I think the watts AXI talk about are 'watts to the prop' as they call it and I'm measuring watts going into the motor. Assuming around 80% efficiency their figures of 79 amps, 1941 watts and 6250 rpm on a 19 x 12 from a 10S lipo would just about be spot on. Funny that really.

Is it revs that caused your magnets to be thrown or high amps? AXI quote figures of 90+ amps for their 5330 but only 5780 rpm at this current. If I reduce my prop to 17" or even 16" my top current should go down into the 60 amps range but revs might go into the 7000+ range I'm guessing. Would I in fact be making the chance of throwing another magnet worse?

Plettenberg suggested I had some sort of harmonic vibration problem with my 370/50. It was the new motor that siezed and the one from the Tiggie which was nearly 2 years old was fine with the same prop, ESC and battery set-up. When it 'let go' it was almost at idle coming into to land. Can't really explain it.


Richard

luc
08-21-2005, 03:50 PM
mmmm...maybe....or different props used...who knows?
I think I had too many amps (60+ in peaks) for the 4130....maybe the 5330 is sturdier.
Anyway, I tested the service repair from model motors (straight to Checz rep) and got back the motor repaired, no cost, in a month...that was good and I recommend it, in case you have any trouble.
I plan to get a 5320/28 (249 kv, same as 5330/18) for a 12 lbs monocoupe (cub like), in 9S. I am still wondering about the prop for a 45A static....I was guessing on 19*12 but I guess now it might be too much....

modeldesigns
08-23-2005, 12:03 PM
Hi Richard,

Many thanks for publishing your findings on the 53 series Axi. These 'first-hand' experiences are worth their weight in gold.

I caught John landing his 111 after a Doodle Bug deploying sortie at the Woodsprings (Bristol, UK) Club E-fly this Sunday. A super day with excellent weather...a big thanks to all at Woodsprings!

Your B-25 pics look most impressive...and it sounds as if your Mustang is going to be too.

Cheers,

Pete.

Johnr
08-24-2005, 03:21 PM
Hi Bundy John and Pete,
Thanks for the info on the drives, you are putting a lot of voltage and current into the 5330!

I did look at the S3i site John and it seems that you have to put 100w into a lump weighing 1.43lbs so that would be too heavy. The 6oz Visaton speakers are very efficient and can provide 20w so this is the standard until somebody can find lighter speakers......... ? It is the sound pressure level (spl)/watt figure that needs to be good for efficiency of sound output. The cone of the speaker is the light bit, it is the speaker magnet weight to drive the coil that needs to be lighter but very powerful.

If anyone out there knows of other specialist high output miniature speaker manufacturers then please let me know.

Anyway, 1lb payload is not the end of the world for a model this size and it works for me!

Regards,

John

John Seidelman
08-25-2005, 03:18 AM
Record the sounds for us when you get her done. Should be Great.....

Leo
08-30-2005, 03:08 PM
Hi everyone,
When searching for real engine sound modules for my 1/5-scale Commander twin, I found this device:
http://www.eaelec.com/sounds.htm
I have sent a request for a gas engine sample, but have not got a reply yet.

BTW, I like the mp3 player idea. One could make recordings of suitable engine sounds from Microsoft Flight Simulator

/Leo

Johnr
08-30-2005, 03:27 PM
Hi Leo,
That site might give some good results, but it will need much more amplification. The 1/5th watt amplifier might be good for boats, but you really need 40watts plus for planes.

I guess there will be lots of companies making these circuits in the future and all power to them. It makes so much difference to the model when the true sound is heard (and the petrol heads go all quiet :) ).

But who can come up with a super light 20 watt (or more) efficient speaker weighing less than 6 ozs? That is my problem area at the moment.

All the best,

John

Leo
08-30-2005, 04:28 PM
The SPB-1 unit is offered without a power amp as well. I have a homebuilt dual power amp I will use for this application.
Speakers with neodymium magnets are much lighter than ferrite magnet speakers with similar power handling and efficiency

/Leo

Bundy
08-30-2005, 10:23 PM
Hi All

I'm still playing with all sorts of ideas on how best to add sound to a big electric. I've built simple a 70watt amp powered from the lipo flight battery drawing only a few amps at peak output and using a real cheap ($6.00!), 120watt, 2 way, 100mm car speaker weighing 10oz. This setup will nearly lift the roof of the building shed and I will take it outside soon to see what effect it has.

I'm powering it from an mp3 player - the web has a whole host of radial sound files out there. The booming flypast ones really do sound good! My initial thinking was to have a series of mp3 files starting with a radial turning over onto low rpm, mid range and high back to low and then shut down. The idea was to step through the mp3 files via a spare(?) channel on the transmitter.

Not sure if this idea would work but I'm now thinking of just using a constant high rpm sound ( anyone tried this http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXJDU0&P=7) and then 'chop out' sections of this high rpm sound wave with a square wave (or amybe a sine wave?) oscillator driven via the throttle channel. Full throttle on the transmitter would give full sound wave and as the throttle comes back the oscillator would chop out more of the sound wave's peaks hopefuly simulating a lower rpm. Any thoughts??

Reading about Earle Aune's 76" Corsair (http://www.strictlyscale.com/earlaune.htm) I'm now not too worried about the weight of the speaker. His 76" F4U weighs 20lb and he has seen them fly at 27lb and is infact saying don't build too light. The Brian Taylor plan I'm building is the 82" version so I'm thinking it will be more important to get a speaker that 'works well' rather than save a few ounces - might even be able to look at 125mm speakers. Obviously this would be different with smaller electrics tho.

Richard

CorsairJock
08-31-2005, 01:40 PM
Not sure if this idea would work but I'm now thinking of just using a constant high rpm sound ( anyone tried this http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXJDU0&P=7) and then 'chop out' sections of this high rpm sound wave with a square wave (or amybe a sine wave?) oscillator driven via the throttle channel. Full throttle on the transmitter would give full sound wave and as the throttle comes back the oscillator would chop out more of the sound wave's peaks hopefuly simulating a lower rpm. Any thoughts??

Richard

I just recieved mine from Tower yesterday (RAM Radial engine sound). GREAT Deal, but really doesn't have the radial sound I was hoping for: sounds way too smooth, not that lopey, almost Harley like sound. Also sounds like the sample may have been recorded from INSIDE the plane, rather than outside.
I plan on using it anyway in my H-9 Corsair: better than nothing, but I'm sure there will be better sounding ones in the future. I hope RAM gets there act together, revises it and does it right, as there is quite obviously a very growing market for such a product, given the explosive growth of larger scale electric warbirds since Li-Ploy batteries became widely available.

luc
08-31-2005, 05:39 PM
would you consider this device (rather light) will give enough sound volume in the air??
thx for the feedback, I am on the list too...:)

Johnr
09-01-2005, 10:38 AM
Hello Richard and Luc,
Don't forget that the unit that you make must not interfere with the radio reception to the receiver. This was my biggest worry that more electronics so close to the receiver could cause interference. The benedini circuit (www.benedini.de (http://www.benedini.de)) does have opto isolation and if the sound power batteries fail then the throttle control to the speed controller will remain active. Thomas will take any true engine sound that you have and pre-programme it into the circuit. He will add in separate start up and shut down sequences if available plus gun sounds etc for activation via a separate servo. He has been fine tuning the circuit for many years and although it is not cheap, I would not want to go through all that development on a scale plane. If a boat or a tank gets interference the consequnces are not so expensive!
John

CorsairJock
09-01-2005, 01:27 PM
Johnr, the RAM units are natually isolated: they have no connection to reciever or receiver battery. They use a separate battery, and switch is servo activated.

luc
09-01-2005, 03:38 PM
corsairjock
can you record and post on this thread the sound of the ram engine sound?
thx

CorsairJock
09-01-2005, 05:15 PM
I haven't installed it yet, hopefully will do so this weekend and take video (with sound) of flight. I will probably initially use a 9 volt battery, but will order a 3S 500mAh Li-Poly, which will allow better/ lowder sound at same weight.

Bundy
09-01-2005, 09:24 PM
Hi All

Thanks for the info on the RAM unit CorsairJock - I was about to order one. If you could post a sample of the sound that would be fantastic. Is there somewhere here to post videos?

Hey John is it possible to reprogramme the sound file in the benedini unit? I hate reinventing the wheel but my main concern is the cost and once programmed not being able to change it. I'm playing with a number of different sound files at the moment and still hope to find better ones and would hate to have to choose just one at this stage. I really would want to get it into a plane and see how they actually sound first. The idea of opto-coupling to the throttle channel is a good precaution and is easy to do - thanks for that idea.

My plan is to power the sound unit and its amp from the motor battery. This will be a 10S4P (2 packs of 5S4P) lipos thus giving me the +- 20volt supply for the amp. These packs are giving nearly 30mins flight on the B-25's AXI so I'm thinking I can afford a few amps for the sound unit and avoid a seperate power supply for sound.

All good tho

Richard

John Seidelman
09-02-2005, 02:29 AM
Can't wait to hear this thing ROAR!

Johnr
09-02-2005, 09:25 AM
Hi Richard,
Thomas Benedini can reprogramme the unit at a nominal charge, but I don't think you can do it easily yourself. Thomas can programme a few (up to 12) other separate sounds as well for you can trigger through the unit but they will not be proportional with the throttle setting. Be careful about powering any unit from the flight battery pack as you might induce interference. Thomas always said that I should use a separate battery for the sound. At present I am using a 700mah 10 cell (12v) nimh pack and at 30 watts plus, the sound lasts for 14 minutes, so it is only just big enough. The amplifiers get quite hot as they are not 100% efficient.

I find that the generation of the actual sound is the straightforward bit as Thomas has done most of the development there, the clever bit is to get it loud enough with seriously affecting the performance of the plane. The other development criteria that you need to consider is getting the electric motor whine suppressed. In my HE111 I have changed away from gearboxes to get rid of that grating sound. A rubber isolation mounting for the engine would probably stop the motor using the fuselage as a sounding box. Good luck with the development.
Hope this helps,
John

Bundy
09-02-2005, 11:12 AM
Hi John

Lots of ideas there - thanks. I will really have to be very thorough checking for interference if I end up using the flight battery for the amp's power. Some rigorous trials with an old trainer will be needed with the power setup of the Corsair.

What sort of sound file does Thomas require? High rpm, low rpm and what length? Other than internet .wav files are there any more definative, profesional recorded sources of radial engine sounds?

Know what you mean about that whine. I first had a Hacker fitted with a planetary gearbox which had a real whine then the Plettenbergs although direct drive really do have a harsh background noise. The AXI 5330 are really very quiet, I will try and get a video of a fly-by with them this weekend. Isolation mounts are a good idea though.

Happy flying

Richard

Gordon
09-02-2005, 08:24 PM
Hi Richard

It's good to meet up with you again, and I'm glad to see you're still in the business of developing big scale models.

When I replaced the geared Maxcim (the noise from the MEC gearbox was far too noisy and intrusive) with an AXI 4130/20 in my 6s4p 6200 Lipo powered Tiger Moth, I thought that all I would hear would be the swish of the prop.

Not so:mad:

The AXI emitted a loud and constant whine at low and intermediate throttle settings, which was eventually drowned out by prop noise at full power. At low to intermediate throttle settings, and especially at the cruise throttle setting, the thing sounded like a Rolls Royce Nene (very inappropriate for a Tiger Moth :rolleyes: ), and I suspected that the tone was coming from the Schulze F32.55 esc.

As I have no other big escs I couldn't experiment using a different one for comparison, so I made the isolation mount system depicted below, and this did the trick. The large black washers are cut from 1/2" diameter neoprene cord.

Now the whine is very subdued at low revs, inaudible at mid to full power, and almost inaudible at cruise power, being drowned out by prop noise. Originally, the airframe had been acting as a louspeaker cone, with the motor energising it.

I made a similar mount for the geared Maxcim in my Kyosho CAP 232 running at about 900W compared with the 700W max of the Tiger Moth, but the gearbox noise was scarcely reduced at all, which I thought was strange as well as disappointing.

Thinks .... since my orginal jet-engine noise must have come from the esc, I wonder if one could modulate the motor current with a full size engine sound?

Gordon

luc
09-02-2005, 09:44 PM
that should come from the esc, as I have 3 motors 4130/16 with no noise.
esc I use are jeti 77 opto (2) and a hacker 48 opto.

Gordon
09-02-2005, 10:52 PM
Very interesting! A clubmate has a 4120/14 with a Jeti esc in a big biplane, and that motor which is rigidly mounted in the airframe sounds just like my 4130 did originally.

My bipe is Solartex covered, and his uses Profilm. One wonders if the covering style has something to do with these two noise phenomena. Do your models have rigid sheet balsa covering, or open structures with fabric or film covering, Luc?

Gordon

luc
09-03-2005, 07:16 AM
std structure wings with front part of the wing covered and back part with open structure.
fuse is plywood/balsa classic.
I don't hink that this may have any influence...
I use alu motor mounts such as this one (on another plane)

Johnr
09-06-2005, 03:54 PM
Hi Richard,
Sorry for the long delay in replying, I did not get a reminder that you had posted. To answer your question about sound files, what Thomas needs is a fairly good recording of the actual motor revving up, and if possible starting and stopping.

Mine was on the net and the revs were not at full power. He took it and adjusted it electronically and played it back to me over the phone so we could agree what the top rpm would sound like. The starting and stopping sounds were located on a separate part of the circuit so that they would activate when you switch the sound on and off. The trick here is to slide the throttle stick forward to tickover when the startup sound is broadcast. Thomas also took a flypast sound and programmed it to a separate triggerable part of the circuit, but this is not the right sound, you need the one where the recorder is standing in front of the plane.
Thomas already has the gun sounds and he has many other engine files although they are not aero engine files.

I have seen Gordon's flexible engine mount. It is an excellent design and it seems to be the right way to go if you have motor whine problems. As most of our large scale WW2 planes will have sheeted structures then they can resonate. This actually helps to amplify the loudspeaker sound if it (or they) are fitted in the wing. The wing sounding box in between the ribs really helps. However with the power that the speakers are putting out on the HE111 they broke the joint between the ribs and the top sheeting, so this needs to be glued fairly well!

Good luck with the cricket, we are doing a rain dance here!

All the best,

John

CorsairJock
09-06-2005, 04:20 PM
OK, I have an R2800 starting up, and idling, about 50 seconds long. Now, if I can only post here:

Looks like a no-go: MP3 is "invalid file". I can e-mail it to some-one (who is maybe more computer savvy than I am).

Bundy
09-07-2005, 10:35 PM
Hi Guys

Thanks for the info John. I've nearly got my sound files sorted (but would love to hear what you have found CorsairJock) and I'll soon be sending them over to Thomas and see what he can do for me. Attached is a pic of the VERY crude test rig I've been using to see what is possible. At 50 meters and 80% volume this thing really does sound the part. I was a little concerned the sound from a real R2800 wouldn't sound right coming out of a 1/6 scale F4u but to my ears and eyes it is just right.

Interesting point about the sound causing structual problems. The Corsair's shape will be built around a solid 120mm central 'box' which will be the sound box. The speaker will mount on the firewall and with fully operating cowl flaps, that big radial opening at the front and venting from the 'box' thru the scale opening under the wings I'm hoping enough sound will get out - time will tell.

I've got an 80" Bronco nearly finished which I'll use as a test bed for the sound system and check for interference problems then I'll be starting on the Corsair hopefully having it flyable by Xmas. I've got most of the bits already with the Robart retracts arriving yesterday. How about a new thread on the electrification of a Brian Taylor 82" Corsair?

Any chance of getting to hear your Corsair sounds CorsairJock by emailing it to me??

As for the cricket John - I'm 44 and can't remember ever not having the Ashes ( altho you poms never actual let us have them!) so I guess it is only fair we give you a sniff of victory to keep you enthused. What do they say - " there is nothing so sweet as the silence of an English cricket crowd" Best of luck :)

Richard

Johnr
09-08-2005, 09:34 AM
Hi Richard,
You are making good progress, glad you have all the files. Corsair Jock kindly emailed me the R2800 starting up sequence and it is really good. Suggest you contact him and ask if you can compare that with what you have, as it would make a really good start to the sequence.

On the subject of sound coming from the rear of the speaker? suggest you should probably do some tests first as you will find that the acoustics may get worse if the sound waves from the front cancel out the soundwaves from the back of the speaker. If you are only broadcasting from the front of the speaker then ignore this comment. I have also been advised that it can help to load the speaker by putting a funnel or horn over the front (like a loud hailer).

The HE111 was flown again last night and it sounded really good just rumbling across the sky. I am sure that soon most scale planes will have sound.

If you do send your files to Thomas, ask him if you can have a larger 'dead band' than me, so that small tickover trim changes will not make the engine roar into life. I have mentioned this to him before, but it would be good to remind him.

Can't bear to watch the cricket!

All the best,

John

modeldesigns
09-08-2005, 12:44 PM
Richard,

Yes, an 82" Electric Corsair build thread would be most appreciated!

Richard, John, CorsairJock,

Keep up the great work on the sound systems.

Pete.

luc
09-08-2005, 03:57 PM
thx to post the tune here...:)

Bundy
09-10-2005, 12:49 AM
Hi All

Thanks for resending the mp3 file CosairJock - got it this time. That is a great sound- where did you get it from? Is there a 'full bore' version of the same quality? The stereo seperation of it adds a fullness to it but I think a 70 watt stereo sound system is a little beyond this first Corsair :)

I think you are right John that a lot of experimenting will be needed to get the best sound. From what I've been reading a well designed bass- reflex vented box would have some real advantages at the lower frequencies and in effeciency but get it wrong and it can be a lot worse than the sealed box. For a sealed box to work at its best they say it should be constructed out of some solid material that will not flex - 5/8" ply or better which is not really practical in a plane of this size.

There is plenty of information on the net on how to design and build boxes for car stereos so I guess I'll have to get my into it and then play a little.

Can't you Englishmen do something about the rain over there? There is cricket to play!

Richard

Johnr
09-10-2005, 09:32 AM
Hi Richard,
It has just stopped raining here, I am getting quite worried. I may have to go quiet for a while...... We are very good at losing, we have had a lot of practice!

Good luck with the experimenting, and the search for the sound of the motor running up, and shutting down - if possible. That start up sound from Corsair Jock is very good.

All the best
John

john

Bundy
09-13-2005, 10:40 PM
Hi All

And hello Gordon - great to see you in here. Just to get it out of the way we all know cricket is just a game and real winner from the Ashes series is cricket. Well done guys but don't too comfortable!

Fantastic idea for motor mounting Gordon. I hope to get a test set-up of the front end of the Corsair with the motor mounted on the sound box done in the next week or so and see what it all sounds like.

I've attached a file here as a zip file. It is a recording of one of the B-25's AXI 5330/18 mounted on a solid aluminium mount turning a 18 x 10 APC-E. Does this zip file format work and does it sound like what you think it should?

Richard

Johnr
09-14-2005, 08:48 AM
Hi Bundy,
Yes, we will probably let you have the Ashes back in 18 months time, but for now now after 18 years, victory is sweet. Don't be too hard on your team, they played very, very well (as usual).

The sound file does work and it sounds good. It appears to have less whine than my 4130/16s in the HE111. So it should be OK to drown out with the sound from the speaker output. However, any sound isolation mounts that you can make for the motor will only help the situation.

What speaker do you intend to use and how heavy is it?

All the best,

John

Bundy
09-15-2005, 09:28 PM
Hi John

Following up our amp discussion - this amp I'm using http://www.dse.com.au/cgi-bin/dse.storefront/4329d60a03e1ff14273fc0a87f9c06da/Product/View/K5401
is rated at 36W RMS continuous into a 4 ohm load when using a 13.8V supply and 70W music output. Without the heatsink it weights 59g (2oz).

The power supply for it must be able to supply atleast 6amps @ 13.8V to stop its muting circuit cutting in if the supply voltage drops below 8V.

There are a few other amps which need further investigating like http://www.dse.com.au/cgi-bin/dse.storefront/4329d60a03e1ff14273fc0a87f9c06da/Export/catalogs/SUPZ6115

I really need to get one into a plane and check for interference problems - maybe the Bronco - plenty of room for a speaker in there.

Richard

Johnr
09-16-2005, 09:44 AM
Hello Richard,
Thanks for the information. It looks like the second amplifier is similar to the ones that Thomas supplied to me. Therefore a bit marginal in output.

With the amp that you have, if you can test it, can you measure what current it is using at full power on 12v? It would be a rough comparison against my two, assuming the efficiencies are rougly similar.

What is the weight with the heatsink? I have found a manufacturer in the UK who supplies prebuilt 30w RMS amps without heatsinks at 70g each and with at 170g. The HY1420 and HY2000 amps are on ilpelectronics.com/amplifiers/audio

I might ask Thomas's advice as to whether either of these would be suitable. The 2000 version seems as if it could be driven directly off the supply pack, if less that 30v. The 1420 version costs £15.

Regards,

John

Johnr
09-16-2005, 11:32 AM
Hi Richard,
Thomas says he uses ILP Electronics and the 20w amp is good but heavy with the heatsink. The 30w amp is only good for plus and minus 12v so it is unsuitable unless we have a specialised power supply. The man at ILP said that it is impossible to get more that 20w from 12v unless the amps are banked up or if the loudspeaker impedance is reduced. I am no electrnics expert, so perhaps you can shed light on this? It appears your amp will work on 12v, so it will be interesting to note the current draw at full load.
All the best,
John

Gordon
09-16-2005, 03:42 PM
Hi Guys

This is a really interesting thread and thanks for keeping it going.

I'm going offline for two or three weeks, but I thought that I'd throw in an address for a pretty cheap 40W amp which should work off a 16V DC source, eg a 5s Lipo.

http://www.maplin.co.uk/Module.aspx?ModuleNo=37737&doy=16m9D

The next item down in the left-hand margin is the pre-amplifier referred to in the write-up.

I know no more than what's in the write-ups about these so they might be no use. However this address, found by clicking the FAQ tab, has more info:

http://www.kemo-electronic.de/en/module/m034/index.htm

The PDF description downloaded from this site does have an English paragraph with mounting information.

John .. one thing to beware of with the 30W amp you mentioned is that it needs an AC power supply, which means that it can't be battery powered, and it looks as if all the higher power ILP amps are the same.

Cheers

Gordon

Bundy
09-17-2005, 01:34 AM
Hi Guys

I was just thinking about pre-amps this morning Gordon because I'm not sure of the ouput levels from Thomas' sound board. Your link shows such things do exist if needed - good to know.

The attached pic shows my test rig at 84% volume ( don't we love digital precision!) with tired batteries in the mp3 player and the family telling me to shut the noise up. At full tilt it gets close to its claimed 6 amps so any regulated power supply derived from the flight batteries will have to able to cope with this load.

The Corsair will have a 8000mAh 10S4P li-po rated at 12C continuous so even with motor loads around 50amps peak there should be room for the sound system to run from the same battery assuming no interference problems are encounted. A seperate battery for the sound system is always possible and I think the weight wouldn't be great issue in a plane of this size.

The weight of the heatsink John is 130g but I plan on not using it instead mounting the TDA1562Q chip onto the motor mount in the airsrtream. The amp has an inbuilt 120 degree overload protection which shuts it down to half power if things get too hot.

You are right that generally it is impossible to get more than 20watts from a 12v supply. From the literature, this amps acts as a normal BTL amp upto 18watts but when a higher output is required the internal supply voltage to the power amplifiers is "jacked up" by using the "Lift -Supply" stages to switch in two external electolytic capacitors. There are no detailed specifications as to how the "lift-supply" stages works.

I've got a circuit diagram for it if this would help explain things.

Hope this helps

Richard

Gordon
09-17-2005, 09:47 AM
Hi Guys

Just another quicky before I disappear:

This website http://p38whitelightnin.com/gallery/ has some video of Lefty's P-38. Both show the full engine start-up sequence with audio, then taxi, then a lot of flying though most of this has music added.

I downloaded the right-hand video and then imported it into Windows Moviemaker. The result was a big bunch of short clips which could possibly be used to make a sound file for start-up, taxi, and perhaps in-flight with some fiddling, if anyone knows how to extract just the audio and then load it into a playback device.

Back soon!

Gordon

Johnr
09-19-2005, 10:24 AM
Hi Richard and Gordon,
This is all really good research, The Kemo 40w amp seems to be music power so it is probably 20rms and equivalent output to the one that Thomas supplies. I like the look of the Kem 50 and 80watt amps though! That should wake em up.

Richard, your amp certainly is performing, as my two amplifiers are only drawing just under 3 amps (total) flat out. Did you make it from a kit and do you know if the supplier sends stuff to pommieland?

I have e mailed Thomas to ask if he can help with a more powerful amplifier.

Best wishes Gordon.

All the best,

John

Bundy
09-20-2005, 09:09 PM
Hi Guys

Yep my 70 watt amp is a kit but was an easy build. If you can solder you can build this one and yes they do internaional mailorder. I got mine from one of their retail outlets which are everywhere here in Australia so if you are chasing one and have any trouble with mailorder just let me know and I'd be able to help you out.

My 2 CD Corsair sound set has arrived and although done for a different target market with lots of fly-bys passes, group engine start-ups and shut- downs there should be enough to send to Thomas. Hope to get that away this week and see what he can do for me.

All good

Richard

Johnr
09-21-2005, 11:53 AM
Hi Richard,
Thanks for the information, I have heard from Thomas that the amplifiers he sold me are 20w music power each, so my two are only delivering 20w rms total! That would explain my lower current usage.

So that means the sound can be nearly doubled using one amplifier. Good news indeed. I will probably order one of the 70w amps and have a play.

Hope Thomas can use your new sound files. Keep up the good work.

All the best,

John

modeldesigns
09-22-2005, 03:08 PM
Hi everyone,

This link should take you to a short video of Johns He111 'running up' captured at Baldock E-Fly (North London) last Sunday. Hope you enjoy the sounds!

http://video.google.com/videopreviewbig?q=%22He111%22+playable%3Atrue&time=0&page=1&docid=-3642080677862199941&urlcreated=1127397208&chan=Uploaded&prog=He111&date=Tue+Sep+20+2005+at+4%3A06+PM+PDT

You may have to download Google Video Player,

http://video.google.com/video_download.html (http://video.google.com/video_download.html)

and need Windows 2000 or higher.

Pete.

watt_the?!
09-24-2005, 09:51 AM
hi all,

wow...ive been looking for one of these for a logn time. Hawker S[ystems (i think) in the UK do a gas turbine one and a bunch of diesels for their trains..

i see that Luc has the polk dr1...thats what im looking for sound for.

The great thing is that this plane NEEDS weight in the nose...so a speaker/amp setup is perfect for it...

I'm waiting with bated breath.

tim.

luc
09-24-2005, 06:50 PM
euh...I have the GP DR1. It still sure needs weight in the nose...I put the lipo inside the cowl...:)

Bundy
09-26-2005, 09:07 PM
Hi Guys

Great video Pete and great plane. Lots of potential for new ideas in adding sound to electrics. Are you inspiring others to have a go when they see what can be done?

My Aircraft Records 2 CD Corsair set arrived and altho aimed at creating an atmosphere with lots of fly-bys there were some great start-up and shut-down sounds. Thomas was more than happy with them anyway so I should have one of his new micro sounds cards programmed up with a Pratt and Whitney R-2800 in about 4 weeks.

Keep up the good work

Richard

irone
09-27-2005, 05:57 AM
I too am looking to add sound to some of my planes but I guess that I am looking in a different area than you guys. As you know weight is a factor with electrics, especially smaller planes. Too heavy and they are dogs.

I am looking for a way to create the sounds by adding a small whistle of some sort to a wing tip so it screames in a dive. Or do you remember using clothes pins and playing cards to rub on the spokes of your bicycle when you were a child? Making sounds like a motorcycle. It seems to me that the same sort of thing could be done at the prop shaft, rubbing something against something else to create sounds in sync with motor RPM.

Just thinking out loud with some low weight, low tech, inexpensive way to get what you want (noise). Any suggestions would be appreciated........

I love the smell of Lipos in the mornings!

TopGun Combat Planes
http://members.ebay.com/ws/eBayISAPI.dll?ViewUserPage&userid=brodiejf

luc
09-27-2005, 06:25 AM
I can't find the site, but these whistles are sold by the manufacturer of the elee bee (wing) in HK.
I got one for less than 2$, sent abroad...
you can put them on the wing or on the plane..

Johnr
09-27-2005, 08:54 AM
Hi Richard and all,
I understand the Traplet Quiet and Electric sound article is now published if that helps with photos etc. I have ordered a 35watt rms amplifier from Oz to try it out.

Thomas sent me a picture of the new micro circuit but I am not sure whether it will upload.

Regards,

John

Bundy
10-02-2005, 09:03 PM
Hi John and Everyone

I've finally managed to clear enough room on the building bench to make a start on my BT Corsair. I'm trying Gordon's isolating engine mount idea and built the speaker into a totally sealed box. I'll try and get it sitting on some wheels in the next week or 2 and fire it all up to see what sound it'll give.

Thomas' micro card should be here by then. Looks tiny in the picture John. Does it do all the same things your one does? Thomas said the dead band on this one programable by the user which should solve that little problem.

Thanks for the info on Q&E. They have been a bit hard to get from the newsagent over the last few months so I might have to subscribe.

Happy building

Richard

Johnr
10-03-2005, 01:33 PM
Hi Richard and all,
That looks very good. You will be frightening all the roos across Oz with that! It will be interesting to see how the engine mounts perform nad how they isolate the whine from the structure.

We both look forward to the new circuit from Thomas. I asked him if it had all the same functions as the TSB4 circuit but haven't had a response yet. It will be good that the dead band will be user programmable.

Not yet received the amp kit yet.

Regards,

John

watt_the?!
10-05-2005, 06:55 AM
i found a company that already does these....

http://www.ramrcandramtrack.com/

my radial is on its way.

they do jet sounds and merlins etc also.

sorry if someone's already posted this.

Cheers,

tim.

luc
10-05-2005, 06:54 PM
thw to post the sound and a pic of the device once you get it

Bundy
10-08-2005, 12:06 AM
Hey Tim - is that the same one CorsairJock was talking about back in post #17? He didn't seem very impressed with the sound. Let us know what you think. Any chance of posting a sample?

Has that amp kit shown up yet John? Really a simple build but do follow the instructions when they say install the big electro capacitors last. I didn't and it did make mounting the heatsink a bit awkard.

Richard

watt_the?!
10-08-2005, 12:10 AM
yeah it is...dang, missed his post.

oh well. will post a recording of it, should have it this week.

Tim.

Johnr
10-11-2005, 02:06 PM
Hello Richard and all,
This is a picture of the new circuit that Thomas is about to release. The only drawback is that it will only do one sound at a time.

Still waiting for the amplifier circuit. Perhaps they are out of stock?......

All the best,

John

eflight-ray
10-19-2005, 07:56 PM
Bundy

I have only just joined this forum, so excuse me if it takes me some time to find my way around the various threads and end up repeating a reply or question.

I was intersted to read that you are building a B25, as I have been flying my own version off and on, (it only comes out on rare occations now), and its now about 10 years old. It would be great to have the correct sound of those radials, especially the start-up. Since I changed from gearboxes to belt drives, mine sure sound better but is almost silent at a 50 yards.

Good luck with your project.
:)

watt_the?!
10-19-2005, 10:33 PM
yeah it is...dang, missed his post.

oh well. will post a recording of it, should have it this week.

Tim.

Well i got my radial sound this week.

not great and not incremental either...i.e. not inline with throttle position.

its either on, or off.

the great big speaker worries me though with that big magnet on the back and how it would interfere with the mag field of the motor/ESC/wiring etc.

me thinks that these things are better suited for larger planes.

(??)

Tim.

Johnr
10-31-2005, 10:25 AM
Hi Richard and all,
Finally received the Oz 70w amp on Friday, it took three weeks to arrive but only a Saturday morning to assemble and test. It was powered by a 40amp 13.8v regulated power supply and fed a large speaker. Although it was working and loud (the wife said the neighbours would soon be complaining), the current maxed out at 2.5amps before the sound started breaking up. Any ideas here Richard?

The heat sink was fitted and the large 6" speaker was easily capable of taking the amplifier output. I am not an electronics expert so my diagnosis skills are not so good. I have checked and rechecked the electronic parts layout and it seems to be correct.

It does say in the technical info that the capacitors do have to recharge so I was wondering whether continuous engine roar would prevent them from having the lull to recharge, but having said that, you managed to get your amp to draw 6 amps!? :confused:

All the best,

John

E-Challenged
11-05-2005, 03:18 PM
Making wing panels into sound radiators should work and I think it's been done. Mini-Olympus gearboxes have a fairly loud sound for some reason. My 54" w/s Aeronca Chief has been accused of having IC power. Four of them on a B-17 etc would sound pretty realistic. Makes me wonder if a gearbox could be purposely designed or modified to make engine sounds.:)

Bundy
11-07-2005, 03:43 AM
Hi John

Sorry for taking so long to get back. I didn't get an email saying there were updates here and I've been too busy with Corsair flaps :eek: to go looking.

I just fired my amp up again now and had it pulling over the 6 amps with the sound file I've sent Thomas. I know the problem you are talking about tho and while not being a electronic buff, I've fixed it by driving the amp with a preamp.

When I was driving straight from the small mp3 player some files start the breaking up/chopping out you are talking about but when driven via a small preamp through the computer I've had no problems and the full 6 amps showing on the Whattmeter. My wife wasn't very happy with the noise but at least she knows where I am!

Let us know if this helps?

I'm still waiting on Thomas to finish his micro sound card. I will post some pics and sound captures when it arrives hopefully in the next week or two.

Amplifing a noisy gearbox via the wing is a novel approach. Maybe a clicking device like kids use on bike wheels:rolleyes:

Getting closer

Richard

Johnr
11-07-2005, 03:34 PM
Hi Richard and all,
Ref the Oz amplifier, you might be right about the input power. I used the headphone output of the garage radio and it broke up when the vloume was turned up.

Thomas sent me an early first development micro circuit plus a 2x40 watt amplifier (12v) as a demo for a British Elelctric Flying Association talk that I did in the UK. It arrived at the last minute and I only had time to do a quick check.

The Micro unit looks very good. :D It is about half the size of a postage stamp but takes female servo connectors. It has a small amplifier built in, so this should be good as a preamp for us model fliers. Thomas had trouble with the first version software for the programing, so it would not give the special sounds. He is working to fix this problem so it might be a few days before you get your production version.

The micro sound circuit is powered from the receiver battery, so the amplifier and its battery must be kept separate. This is good, as potentially is could allow us to use other amplifiers using the higher voltages from the main power batteries. (interference permitting that is).

The micro circuit does not have opto-isolation, we will have to watch this as well. Suggest your first one is switched on by a separate servo so that it can be switched on and off at height for testing. Are you going to have the micro circuit or the larger TSB sound unit?

The amplifier looks excellent :D and uses a similar (but not identical) Phillips chip as the Oz amp. It is much more compact, lighter and simpler that the Oz circuit. However, once again, it is suffering from low power consumption. I could only get 1.7Amps at 13.8v = 23w, but Thomas advises that I need to regulate the input by reducing the value of the 10k input resistor. That is similar to what you were saying isn't it, and it makes good sense. I might try and get a variable potentiometer to be able to work the two speakers to their maximum 20w true.

We are getting there.

All the best,

John

Bundy
11-13-2005, 10:36 AM
Hi John and Everybody

Really need to check in here more often - the auto notify doesn't always work. Busy time of year for us too. We live in the sub-tropics in Queensland and grow hydroponic culinary herbs for the restaurants of Sydney and Melbourne. We are having one of those hot, wet summers which is brilliant but creates lots of work for us.

Still haven't heard from Thomas as to when I can get a micro sound card but from what you are saying it should be good. Do I understand correctly that the new micro sound card comes with a 20watt amp based on a Phillips chip? If this is so then it should fill the bill of the preamp well after a little fiddling to get the best results. That Oz amp will happily sit on a 6 amp draw if the input is at a suitable level. Still a challenge to derive this power supply from the 40 volt motor battery but will see what can be done because it will simplify things greatly.

Actually I'm almost up to the stage of needing the sound card in my Corsair build. Before I start planking the fuselage, I'm sorting out where everything will go. With scale retracable tailwheel and arrestor hook, working canopy, full cockpit, sound box and working cowl flaps along with a 10S4P lipo I'm fast running out of room. Can the sound card and its functions be worked from an E-switch and not a servo and micro switch? Physical room and radio channels are both tight even at 1/6 scale and 82".

I've subscibed to Quiet and Electric Flight but I think they have started with the wrong issue. Which issue was your artcile in? Might still be able to get in the shops here which are still way behind.

Will send some pics and sounds when I get something.

Happy flying

Richard

Johnr
11-14-2005, 09:25 AM
Hi Richard and all,
I wish it were hot here, we have just had our first frost.

I have posted a picture of the micro plus the new Benedini amplifier rated at 2 x 40watts against the Oz amp. The micro has a 1 watt amplifier in it I think. It is powerful enough to take his new amplifier into producing distortion. Thomas advised me to adjust the output of the micro with a 10k ohm potentiometer. Have done this, but still stuck at 2 amps at 15v on his amplifier. The speakers I am using are 8 ohm versions, so really I need to try 4 ohm speakers.

Thomas is using a spare channel to start and stop the circuit, so you only need to make a female to female extension lead and it plugs into the pins on the board. One more for the throttle and one plug for the output to the amplifier. I am sure you will not have trouble finding space for this circuit!

I will have to check the QEFI edition, but if you can see a previous edition with the yellow nosed 109 on the front, it is that one for my BT conversion and the next one for the sound.

It would be really good to see the Corsiar build when you have a photograph.

All the best,

John

EddyKilowatt
12-09-2005, 08:16 PM
Not to interrupt this interesting disussion of amps and speakers, but from putting sound in model trains I've learned that the speaker enclosure is at least half the battle. (Actually I learned it from hi-fi magazines, but fooling with trains really brought the lesson home.) Model train folks have gotten adept at putting speakers in die-cast metal boxcars that are carefully sealed to prevent air leakage, and things like that.

Without an enclosure, a speaker can't produce low frequencies -- technically, any frequency with a wavelength larger than the speaker. The enclosure keeps the sound waves from the front and back of the speaker from cancelling each other out -- it has to be rigid, so sound can't get thru it, and it has to be well-damped, so it doesn't resonate (rattle, buzz, etc). Problem is, most successful speaker-enclusure materials are heavy and dense -- like plywood and MDF for hi-fi speakers, or the die-cast zinc mentioned above. :(

I don't think this is an insurmountable problem, but it is going to require considerable experimentation and probably modification of the airframe, to achieve an installation that does justice to the sound of a big radial. I think the speaker and the amp will be two of the easier parts of the problem.

It'll be worth it though... sound seems like a gimmick at first glance, but you quickly find that it adds a heck of a lot to the modelling and "oh-wow" experience.

Ed

Johnr
12-12-2005, 11:04 AM
Hi Ed,
You are right that the speaker cabinet is a large part of the concept and that we can't install anything too heavy. At the moment the sealed wing cavities works well for the sound boxes. They also works efficiently as the sound is emitted downwards. We are all experimenting and the definitive way will emerge eventually. As you have probably seen, Richard is fitting a good solid sound box in the cowl. If only we could find lighter speakers, as the amplifiers and sound cards are fairly well developed.

Do you know of any lightweight efficient speakers? Mine are 4" Visaton 4 ohm speakers at 20w handing power, weighing nearly 6 ozs each.

Richard, I tried the Benedini amplifiers driving the two HE111 4" 4 ohm speakers and eventually blew the coil of one speaker! Therefore the new 1 oz weight amplifier is very good and I will experiment with fitting it with the micro sound card into a test plane. Which sound unit are you getting, and are you going to buy a Benedini amplifier or use the Oz amp?


All the best,

John

Flite-Metal
12-14-2005, 02:12 AM
A Piezo plastic speaker and a 5 watt audio amp with a digital audio source playing the sound of an appropriate number of cylinders won't be difficult to put together. Its light weight and won't draw down too much power on a seperate battery. Recording a Stuka, B-17, B-29, B-25 sound won't take
minutes with as many sound bytes that exist on the web.

Bundy
12-14-2005, 05:06 AM
Hi All

Finally have things sorted with Thomas and have just bought the TBS Micro sound card along with a programming adaptor so I can access all its features. You can apparently load your own sound files on with this. From what I can understand at this stage, the only real compromise with the micro sound card is not being able to play multiple sounds at the same time but personally I'm not too worried about this. Should be in the mail before Xmas and I will put it into a test plane very early in the new year.

I'm planning on using the Oz amp at this stage and see how things go from there. With its built in 1 watt amp I shouldn't need a preamp. I now need to look at BEC ideas to see if I can derive a regulated 12volt 5amp supply from the 10S4P flight battery and do so with no interference issues. There are number of circuit ideas on the net so it is time to start a testing program.

Just found a copy of your article in Q&E Flight John. Fantastic pioneering work you've done! I'm sure that one day sound in electric planes will be main stream but it sure is fun to be involved at this stage.

Hopefully a video of the test plane in the next few weeks.

Richard

Flite-Metal
12-14-2005, 01:37 PM
Don't believe I would take a chance on crashing a plane for sound
sake...use another battery...

Also, you can create a multiple sound byte using an audio editor in a PC.
Mix the multiple sounds to form a new sound byte. Typically you will run
into a memory issue. I would think use of a lower voltage requirement amp
would be helpful as well. Radio Shack should have everything needed for
this.

Johnr
12-15-2005, 10:19 AM
Hi Richard and all,
I don't seem to get update e mails informing of a post. Do others get this problem?

Glad the TSB micro is in the post to you. It is very small and a bit fragile (bendy) but seems to work well. Hopefully Thomas has sorted out all the programming problems. Thanks for your comments about the article. It has been a long haul but worth it. The petrol heads can't do this!

You will need to make up some extension servo leads with female to female conections for the male sound card connectors.

I am about to test the prototype micro (that Thomas sent) in our trainer model 'Heap of the Week' - picture attached. The speakers and power supply are far too small but it will be a good test for interference. Ground range is fine, so we just have to wait for the English weather to settle down........

Ref your power supply quest, we are looking at doing this as well but as I am no electronics expert and I cannot select the appropriate device. A friend is working on this. Good luck with your search. If we find anything then we will let you know.

Hi Ed, Thanks for your advice. I started at 5 watts but it was not nearly enough. 50w is better! Seriously though, we should be able to manage over 40w soon. The heavy speaker(s) are now the weakest link and I have just burnt one out by driving it too hard with the new Benedini amp. At one oz wieght it is very powerful. I have been conservative and just used a separate battery supply for the sound, but a regulated supply from the flight batteries has to be better - if it works!

I keep asking, but if anyone knows of any lightweight speakers that can take 30watts plus, then please advise. At the moment we are using 4" 20-30w conventional speakers at 5 1/2oz each. Unfortunately piezo speakers cannot seem to handle this power. Any other ideas regarding specialist speaker suppliers? I have been through the complete Visaton range in their catalogue but to no avail.

All the best,

John

Leo
12-16-2005, 08:33 AM
I keep asking, but if anyone knows of any lightweight speakers that can take 30watts plus, then please advise. At the moment we are using 4" 20-30w conventional speakers at 5 1/2oz each. Unfortunately piezo speakers cannot seem to handle this power. Any other ideas regarding specialist speaker suppliers? I have been through the complete Visaton range in their catalogue but to no avail.

John
These car speakers with neodymium magnets looks good.

http://www.blaupunktusa.com/BlaupunktUSA/Products/Speakers/SpeakersProductDetail.aspx?NRMODE=Published&NRORIGINALURL=%2fBlaupunktUSA%2fProducts%2fSpeaker s%2fOverdrive%2fCoaxial%2fODx402%2ehtm&NRNODEGUID=%7bE9EDE67D-3D6A-485E-B47D-0DC0A9D94DE6%7d&NRCACHEHINT=Guest

Johnr
12-16-2005, 10:10 AM
Hi Leo,
Thanks for that. I checked it out and the power handling capability and size are great but the weight is 0.86kg! A bit heavy for our models, but thanks for your input. Any other suggestions welcome.
All the best,
John

Leo
12-16-2005, 11:07 AM
It looks like the specified weight is including shipping package (Beauty Box) and grille
The weight of the neodymium magnet is only 2 oz. for the 4" speaker, so I´m sure the speaker alone is very light.

/Leo

Johnr
12-16-2005, 12:16 PM
Hi Leo,
I have sent for a catalogue so I will check it out, but the lady at the phone help line said that weight was the nett weight of the speaker. I hope she is wrong!
All the best,
John

Leo
12-18-2005, 03:33 PM
the lady at the phone help line said that weight was the nett weight of the speaker. I hope she is wrong!

John

Hi John,
I am sure she is wrong, The image below shows the Blaupunkt ODx compared with a conventional ferrite magnet speaker
As far as I know, the neodymium magnet is 400% more efficient than ferrite

Good luck,
/Leo

cyclops2
12-18-2005, 07:47 PM
About the amount of power?
I have heard a model STUKA SIREN at a air show from 50' away in a dive. Fair on fear and loudness. Wing span 80 + ".
My 8 ' WW PTboat has a 200 RMS Watt 2 chan. ampl.-- 8 big car speakers. At 100' it is realistic for a PT boat. No furthurer away. At 1/10 scale thats 1,000' life size.
I Have to wear ear plugs for tune ups.
It takes a heavy or big speaker to push sound.

Johnr
12-19-2005, 09:50 AM
Hi Leo, Richard and Cylops,
Thanks for the advice Leo, in your picture the speaker certainly does look small and lightweight. I am not sure if that one is available in the UK as the lady on the phone was struggling with part numbers. When the catalogue arrives then I should be able to find the true weight.

Cyclops, you are right in saying that we do need as much power as possible, but we do get the advantage of sound being broadcast down from above. With electric flight we have sleepless nights worrying about every additional gramme, and we have some conflicting criteria, but that is the fun of it!

Hi Richard, have you got that Micro sound unit yet? the test model 'Heap of the Week' flew yesterday with the micro amplifier and small speakers in action. Although the poor little model struggled to get to height, a five minute flight at altitude and distance gave no interference problems.

So far so good.......

All the best,

John

cyclops2
12-20-2005, 09:05 PM
I am only telling you this because I am a pushover.
Try a simple prototype of this.
A thin stick, like a cut down popsicle stick, epoxied to a 280 or 400 size motor shaft.
It rotates from the same voltage as the main motor.
Have it strike a different size -width- rigid sticks. Some very soft, reeds of long length to get a light weight sound maker.
I did this in a small boat. nice dull engine sound.
CHEAP_CHEAP.:)
Took a while to get it right.:(

Johnr
12-21-2005, 12:22 PM
Hi all,
Just to say that Visaton have now confirmed that the R 10 S speaker is the lightest 100mm version they make at 160 grammes, and a Blaupunkt ODX92 speaker (92 mm dia I think) weighs 164 grammes. This must be the correct weight as it was taken out of the box and weighed by a supplier . The Blaupunkt speaker may handle a little more power than the Visaton, but it is considerably more expensive. The ODX132 weighs 300 grammes plus grille.

Thanks for all the positive suggestions. We keep looking.........are there any other ideas of any manufacturers of specialist lightweight speakers?

Thanks Cyclops, that would probably work as an engine simulator, but to get the genuine engine sounds we torture ourselves by making it complicated!

All the best,

John

Bill G
12-22-2005, 04:53 PM
I am only telling you this because I am a pushover.
Try a simple prototype of this.
A thin stick, like a cut down popsicle stick, epoxied to a 280 or 400 size motor shaft.
It rotates from the same voltage as the main motor.
Have it strike a different size -width- rigid sticks. Some very soft, reeds of long length to get a light weight sound maker.
I did this in a small boat. nice dull engine sound.
CHEAP_CHEAP.:)
Took a while to get it right.:(

An unbalaced prop and a loose spinner make very nice simulated engine sounds also, as the harmonics vibrate through the plane. At specific rpms, it really livens up! Actually, I've thought of using Cyclop's idea before, as it is a bit easier on the plane.

cyclops2
12-22-2005, 06:45 PM
The turbine sound is easier if you just cut down a 5" prop to 2" or 3" dia. And cut saw slots EVENLY into the raw blade ends. Use old cheapies.:)

modeldesigns
12-24-2005, 01:31 PM
Hi Everyone,

With help from the John Ranson we have shoe horned into a Hanger 9 Corsair cowling two 4" Visaton speakers. Here is the link to a short video of the result:



The sound file is off my PC and to test it I simply unsoldered the speakers of my computer and soldered the Visaton speakers into the same circuits.

Assuming we can arrange a 12V regulator and power the speakers in the model off the flight pack and Johns tests with the lightweight amplifier are successfull, then the (ball park) additional payload the Corsair will have to fly with is 16ozs. That's about the same difference we had going from round cells to LiPo, so it should be possible on the airframe.

Have a great Christmas,

Pete.

modeldesigns
12-24-2005, 01:34 PM
Try this:

<A href="http://video.google.com/videosearch?q=%22Electric+Corsair+with++engine+sou nd..."+playable:true">http://video.google.com/videosearch?q=%22Electric+Corsair+with++engine+sou nd..."+playable:true

modeldesigns
12-24-2005, 01:39 PM
I'm having trouble getting the link to paste:

<A href="http://video.google.com/videosearch?q=%22Electric+Corsair+with++engine+sou nd..."+playable:true">http://video.google.com/videosearch?q=%22Electric+Corsair+with++engine+sou nd..."+playable:true

modeldesigns
12-24-2005, 01:51 PM
Ok, try this. Go to Google Video:

http://video.google.com/

In the search bar type in:

Electric Corsair with sound

Left click over the picture, allow the buffering to finish and replay it.

tahustvedt
12-25-2005, 09:54 PM
This is so cool! Makes me want to get a warbird just so I can try it. :)

Is there a video of the He111 in the air? The ground run video was awesome!

gofaster72
12-29-2005, 10:49 PM
;) Love that merlin sound. . . .

gofaster72
12-29-2005, 11:12 PM
Adjustable servo delay on retracts, no more slamming up and down.

tahustvedt
12-31-2005, 05:23 PM
Johnr,

Do you know which airplane engine sounds Benedini has available? Spitfire/Mustang/Hurricane would be suitable. I have read through this whole thread but am still not sure about a few things... What electronic components would I need to get from benedini to add sound to a Warbird? I don't see any amplifiers listed on the products-page on www.benedini.com (http://www.benedini.com), but he mentiones that he can deliver them.

Gordon
01-01-2006, 10:55 AM
Hi Pete

This shorter link works :)

http://video.google.com/videosearch?q=Electric+Corsair+with+sound&btnG=Search+Video

Gordon

Johnr
01-03-2006, 02:46 PM
Hi all,
No video of the HE111 flying yet, but camera man Pete might be able to do one the next time we meet. I have attached a still picture of the HE111 for the time being. The V1 is also radio controlled and released at height. No sound on that yet!

Over Christmas the HE111 was fitted with the new Benedini Micro circuit plus the new amplifier and it has now had two long flights. No interference problems encountered so that bodes well for the future. The output sound is certainly louder and it seems about right for the model now.

To my knowledge, Thomas Benedini only does the radial engine sound and the Merlin engine sounds as yet, but if you have a digital sound file of the engine you require, then it can be e mailed to him for programming onto the sound card. You will need a 'start up' sound file, 'running up' sound file and preferrably a 'shutting down' sound file. These are availbale on CDs and sometimes on the web.

The new amplifier may not be shown on the website yet, but he says he will supply them and it is very powerful and very light, see previous pictures.

Have you received your Micro circuit yet Richard?

All the best,

John

tahustvedt
01-03-2006, 06:01 PM
Did you use the Merlin sound in your He111? Right now I'm looking at getting a YT-International Spitfire. I contacted Benedini and got a reply today where he suggests the TBS Micro and a 2x40 W amp.

I was thinking that It must be possible to lighten the speakers a little by making a wooden or composite frame to replace the original steel part. It might work fine as long as the alignment is correct. Might be worth a try at least.

I have collected various Merlin sounds from the internet. These are the best I found: http://www.enrarot.net/merlin.zip

Johnr
01-04-2006, 10:01 AM
Hi Tahustvedt,
Yes the Merlin engine sounds were used on the HE111, but it was from a Mosquito so there are twin Merlins. Your sounds are very good and Thomas could use them. He could alternatively use part of my sounds as the 'twin start up' could be cut back to one, and the shutdown is a bit better as there is a bit of popping as it backfires to a halt. Your running sounds and tickover are better for a Spitfire. Well done for finding the files, where did you get them? I see there is a 109 shut down and I am looking for other sounds of the 109.

I would doubt if you could lighten the RS10 speakers much, as the weight is in the ferrite magnet. It may be possible to drive a single ODX92 Blaupunkt speaker from the Benedini amplifier, but it would need some experimenting.

If everybody keeps hunting then we are bound to find something light. NXT speakers use flat panel technology but do not seem to be small enough yet.

All the best,

John

tahustvedt
01-04-2006, 12:45 PM
The BF-109 sound is from the "German V-12 Sounds" sound set on http://www.simviation.com/fssounds.htm and there are more good sounds there as well. Most of the Merlin sounds I got from a "Supermarine Spitfire MK IXe" at http://www.flightsim.no/cgi-bin/file/search.cgi?query=Supermarine+Spitfire+MK+IXe

I have a fantastic sound of a ME BF-109 taxiing and idling. I don't remember where I got it though. Here it is: http://www.enrarot.net/me109taxi.wav

Bundy
01-05-2006, 12:35 AM
Hi John And All

We've had a really busy few weeks over Xmas with work, visitors and surf! Living at the beach in Queensland in summer isn't good for plane building when there is a wave!

With apologies to Peter Plumb, the designer of the full-size CrackerJack and Dennis Tappsfield ( does anyone know if Dennis is still doing circuits?) who draw up the 1/3 scale plans back in the mid 80's, here is my (well used!) Crackerjack set up as a sound card test bed. Putting the sound of a Pratt and Whittney R-2800 in a 2 cylinder, 35hp DAF powered homebuilt is not right but I've done it anyway.

The photo shows a very crude but servicable set-up. Everything is running off the motor batteries - the sound card via a 5 volt regulator ( Thomas says a max of 5 volts for the sound card and he is right - 6 volts and you have fireworks!) and the amp via a 12 volt regulator with a current expander circuit allowing a regulated 12 volts at 6amps using a standard 7812 regulator. The motor is a AXI 5330 turning a 20" prop and a Jetti 90 amp ESC. This flies the 18lb Crackerjack at 1/3 throttle - plenty there for the Corsair!

On this first outing I found very slight interference at full power, sound on, aerial down and at 30 m distance so I chickened out from a full blown test flight. I flew with the sound card on but not the amp and had no problems.

There was certainly plenty of sound with this setup. I now have a voltage divider from the sound card's 1 watt amp to the 70 watt amp after managing to blow up a 120 watt speaker! The attached video is with this divider about half setting.

Next step is to tidy up the wiring probably causing the interference and fly it with full sound. The interference was very minor and I've flown with worse but I want this to be right for the Corsair. If I still have interfence I'll put a radio operated switch on the sound system as you suggested John.

Great to see all the input on this thread - just wish the system would notify when there is an update.

Richard

Bundy
01-05-2006, 12:58 AM
The zipped video is too big to post here so I'm posting on Google Video now. When it is verified I'll let you know - Sound Test 2.wmv is its name.

In the close-up pic attached to my last posting the sound card is the little circuit board hanging out on the left. The heat sink is way too big for what is needed but weight is no problem in this set up.

Google Video the best place to upload videos to??

Richard

modeldesigns
01-05-2006, 10:22 AM
Hi Richard,

Great trials you are conducting and we all look forward to seeing (and hearing!) the video.

I have used the Google beta video hosting three times now and it seems ok. There may well be other sites that offer a similar service but when i looked, only Google allowed videos of 130mb (my Hanger 9 P-47) to be uploaded FOC. It takes around 24hrs for verification in my experience.

Pete.

Johnr
01-05-2006, 02:24 PM
Hi Richard and all,
Well done that man! Interesting to hear about the power supply circuit, can you tell us how you did it? Do you think that it is this that is giving the interference? Good luck with your tests.

Thanks Tahusvedt for the links, I have now bought some CDs of different engine sounds and I think there is enough for the ME109 for the future.

More searching for speakers has shown that the Blaupunkt speaker is the best so far for power output at 30w rms. The Visaton 4" RS10 is 20w rms.

All the best,

John

thomdoe
01-05-2006, 02:36 PM
I have a depron F117, runs silent and hunts like a shark, as it should. Check out rcsuperpowers.com

sailr
01-05-2006, 09:17 PM
Went to google video and searched for Sound Test 2.wmv without any luck. Is it still there?

tahustvedt
01-06-2006, 09:07 PM
I just ordered a YT-International Spitfire to electrify with one of my AXI 4130/20 (or a home-wound 4130/24 turn) on 8S. Should be much more powerful than the prototype was.

The impedance of the Blaupunkt ODx 92 is 4Ω just like the Visaton, so shouldn't it be a straight swap? Do we really need the tweeter in the center of it?

I looked around on the BP site and the THx series seem to be even lighter than the ODx. If the THx102 is the same as the THx402 on the american site, then it has a magnet weight of just 1 oz and 40 W RMS power handling. They are a lot cheaper than the ODx92 as well.

Bundy
01-09-2006, 08:08 AM
Hi All

Still waiting for Video.Google to do their thing. Video has been verified and should be "live shortly" but that was Saturday!

Think I've got the interference sorted out and plan to get out to the flying field this week and test it out for real. I should get more time this week and will give all the details. Looking and sounding good tho :)

Richard

modeldesigns
01-09-2006, 11:26 AM
Hi Everyone,

John Ranson very kindly spent the time and together we fitted his Benedini micro sound card and high power amplifier into the front of my Hanger 9 Corsair. The card is programmed for John's HE111 and hence emulates a twin, liquid cooled V12 sound - most unappropriate for a Corsair(!) but the mission was to flight proof test the hardware, and we achieved this yesterday. Only the one, short flight but VERY encouraging on the sound volume and no interference experienced.

Here are some ball park weights for anyone contemplating a similar project:

Two 4" Visaton speakers 10ozs
Speaker sound box/motor mount 3ozs
Sound card/amplifier 2ozs
3S 1600mAh power source 4ozs
Additional tailweight(!) 1ozs

Without sound the Corsair had a flying weight of 9lbs, with sound it is now 10lb 4ozs. I really didn't think sound was feasible for models of this size but the Corsair felt safe and landed without wrecking the U/C!
The plan now is to change the card and fly it on an aircooled radial sound.

Cheers,

Pete.

Johnr
01-09-2006, 11:41 AM
Hi All,
Congratulations to Pete for the bottle to fly the Corsair with the extra weight. It sounded really really good and in the murk of a winter's day in the UK it was difficult to tell that it wasn't a model with that engine roaring, -even if it was Merlins.

I have just been given the actual weights of the Blaupunkt ODX 92 (3.5" dia) speaker at 150g for 30wrms, and the ODX102 (4" dia) speaker at 200g for 40w rms, so it may be that we can get away with one small speaker rather than two and save a lot of weight.

All the best,

John

Bundy
01-10-2006, 09:50 AM
Hi Guys

Really encouraging stuff you guys are doing! Any chance of a video of it in flight?

I hope to fly my test rig this week. I think I've sorted the interference trouble - nothing to do with the sound card actually but I need to get back out to the flying field to make sure. I've now blown-up 2 speakers rated at 120 watts playing with this amp. Not sure how this is posssible but new (heavier) speakers will be interesting.

Video of the first hop is up at http://video.google.com/videoplay?docid=1780933562024424649

Richard

modeldesigns
01-10-2006, 10:30 AM
Hi Richard,

Congratulations on the video...a Cracker Jack on 2800hp should prop hang i reckon!!!

It does sound really good and with plenty of volume. I will be obtaining my own sound module and amplifier soon from Benedini programmed with the air-cooled radial sound. Then it's back in the air with the Corsair and i will try to get some video.

That's a handsome looking strip you operate from.

Anyone for lots of white smoke on start-up?!...where will it all end!

Pete.

tahustvedt
01-10-2006, 05:28 PM
I just received a sound-test file from Benedini with the sounds I sent him but they just sounded like all the sounds put together into one long clip.

Doesn't the system change the pitch of the sound to follow the throttle level?

tahustvedt
01-10-2006, 07:59 PM
I edited the sound files now for testing. I matched the volume of all the files and reduced the pitch of the end of the starting sound to give a better transition into low idle. I crossfaded the sounds together end to end, like I imagine the TBS does, and used doppler effect to simulate increasing rpm in the later sounds. Then I used the doppler effect to simulate a fly-by, a bit optimistic in the fly-by though. :)

http://www.enrarot.net/merlindemo01.wav

Here's another demo demonstrating how the low idle and modified shutdown work. They are not crossfaded.

http://www.enrarot.net/merlindemo02.wav


I don't really know how the TBS behaves. I'd love to see a video of a model with the system being started, accelerated into full throttle and then stopped again.

Johnr
01-11-2006, 08:51 AM
Hi Tahustvedt and all,
My development TBS Micro certainly does give proportional throttle sound to stick position. The TSB4 larger sound card also does this for the Mosquito sound on the HE111. Peter should have some vidoes soon available to show this effect when we fitted the development Micro onto his Corsair.

What model are you going to put it in and what speakers are you going to use? I have just ordered a couple of Blaupunkt ODx 92 speakers to see if it is possible to just use one in a smaller model.

Richard, can you tell us how you did your voltage regulator and how you solved your interference problem?

All the best,

John

Bundy
01-11-2006, 10:17 AM
Hi All

Attached is the circuit I'm using to regulate one of the two 5S4P lipos which provide power to an AXI 5330, Jetti 90 amp ESC and 20" prop. It provides a regulated 12 volts at a measured short burst of over 6 amps to my 70 watt amp. I have a trim pot wired as a voltage divider between the 1 watt amp of the micro sound card and the input of the amp. By turning this trimpot the sound just keeps going up, the measured amps keep going up into the amp with the weak link being the speaker. At around 70 watts of power going into the amp - a full 6 amps - the cheap 120 watt car speakers I've been using have 'smoked'. Very early days of playing with this set-up but the potential seems to be there.

My interference I think is a case of if you look hard enough for something you will find it. I expected some interference running both the amp and motor from the same battery. So I kept extending my range check until I found it at about 1.5 times my normal check. By dramatically shortening my ESC battery wiring, moving it well away from the receiver, tidying up all the other associated wiring and tightening a suspect transmitter aerial it now passes the 1.5 times normal range check with motor and sound at full bore.

So next step is back to the flying field. I'm all charged up now and plan to head out tomorrow morning early and come back with a video of a successful flight with sound.

Watch this space.

Richard

Johnr
01-11-2006, 10:44 AM
Hi Bundy,
Thanks for the info on the voltage regulator, is it a simple chip or a circuit that you had to make? Can you photograph and post the electronics? What is the maximum imput voltage that the regulator can take? Questions, questions! Sorry about this, but it will help for us to minimise the weight problem on smaller models.

If you have a ferrite ring, then I would really suggest that you fit one to the throttle lead next to the receiver. It is good practice anyway and they do make a significant difference to interference rejection. About 6 or seven winds will do the trick.

The Blaupunkt ODx 92 speakers have just been delivered so I will be able to report back on these soon.

Good luck with the test flight Richard. When the petrol heads go quiet you will know that you are on to a winner.

All the best,

John

tahustvedt
01-11-2006, 01:41 PM
What model are you going to put it in and what speakers are you going to use? I have just ordered a couple of Blaupunkt ODx 92 speakers to see if it is possible to just use one in a smaller model.


I plan to use the system in an ESM/YT-International Spitfire XIV. http://kmp.ca/rcpics/spitfire/spitfirepicspecs.htm

It's a fairly big model but mounting speakers will be a challenge I think, so the smaller the better. I'm getting it some time next week.

I second the recommendation for using ferrite rings. They really help!

sailr
01-11-2006, 01:58 PM
You guys are amazing! Very impressive developments with the sound systems. Now if you could get that into a "ready to install" package, I'd love to be your U.S. Distributor!

Jim Slaughter
CEO
Hurricane Flight Systems
Suncoast Hobby Imports
www.FlyHurricane.com (http://www.FlyHurricane.com)

Johnr
01-11-2006, 03:27 PM
Hi Tahustvedt and all,
Like the Spitfire! It is off the subject and there is nothing better than flying a Spitfire, but I expect you know that the Mk 14 can prove to be a handfull on takeoff. You may need full up elevator when it starts rolling and to be quick on the rudder. Good luck anyway! Are you intending to use one speaker or two? Where are you based? Are you near Thomas? I would like to fit sound to my 68" ME109 after seeing and hearing the growl of Pete's Corsair.

The Blaupunkt ODx 92 speaker does weigh 152g and you are right that the tweeter is not really necessary. However, it looks integral to the unit and the supply wiring goes through the central tweeter to the main coil, so it does not look as if it is easy to remove. At 30wrms and 90w peak I hope it will take the power! Richard has blown two and I have blown one Visaton R10s so we know there is a risk, but the weight needs to come down some more for the smaller models.

Hi Jim, we are all doing it for the fun and Thomas is the man for the brains on the circuitry.

All the best,

John

tahustvedt
01-11-2006, 03:56 PM
I live in Bardufoss in northern Norway, so I'm far away from Thomas. I expect the narrow and rearward landing gear of the Spitfire makes it a handful, but I think I can handle it. Sounds like fun. ;)

I haven't thought much about how to mount the speakers because I don't have the model with me yet. Do you have any suggestions? I see you mounted yours on the underside of the wing on the He111.

Johnr
01-11-2006, 04:12 PM
Hi Tahustvedt,
Is it cold up there? I went to Ivalo in Finland a few years ago, but that was to see the midnight sun.

It seems to be the long Griffon nose of the Mk 14 Spit coupled with the close proximity of the wheels to the C of G that make that particular mark a bit of a handfull on takeoff. My electric BT ME109 has exactly the same characteristics. I built a Brian Taylor Mk 14 Spit (I/C I admit) a few years ago. The earlier marks are easier. Still you won't have a problem getting the C of G right, and you can probably mount the speaker(or two) in the wing radiator positions. Then you could fit all the other electronics and power supplies in the nose away from the receiver. Is that what you thought?

Regards,

John

modeldesigns
01-11-2006, 04:26 PM
Hi tahustvedt,

The YT Spitfire looks great and is a good size to handle experimentation. It will good to here of your electrification and addition of sound.

In my opinion, the two underwing radiators on the XIV should make an ideal location for the speakers. It's amazing how things evolve, but now sound IS viable on E powered models i find myself looking at all the prototypes to model that will offer the best location for speakers!

The pic is a currently flying PR XI, fabulous colour scheme...and twin radiators!

tahustvedt
01-11-2006, 05:44 PM
It's warm today at around 0°C. It's usually between -10°C and -20°C this time of year but it will drop to below -30°C occasionally.

The flap servos sit inside the radiator cowlings, but maybe there's still room because it's a pretty big plane. I'll have to see where they can be mounted when it gets here. The prototype Spitfire flew well on a RCV 91CD 4-stroke which, compared to my Axi 4130's, is a weak engine. I have a 4130/20 which spins a 17" at 7000 rpm on 8S lipos, and a home-wound 4130/24 that spins a 20" at 5000 rpm and makes a rocket out of my 65" Velox aerobatic plane.

The instructions for the TBS Micro mention a programing cable. From what I understand it's possible to upload new sounds from the computer using the cable.

tahustvedt
01-11-2006, 09:01 PM
I played some more with the sounds and I think I have some really great startup, idle, low rpm and shutdown sounds now. I'm still struggling to find the low-highspeed sound. The ones I have sound weird in the transitions. I made a demo simulating startup, taxi and shutdown: http://www.enrarot.net/taxidemo.wav

Bundy
01-12-2006, 02:38 AM
Hi All

Wow tahustvedt -10C to -20C is doing it hard. It was +27C at 6:30 this morning out at our flying field. I guess it is just whatever you are used to :)

My maiden flight with the sound card on board was flawless this morning. No interference of any sort but I did put a ferite ring on the throttle lead for good measure - thanks guys!

The video titled "No Interference" is currently waiting verification at Video.Google.com and should be up in a few days. Wind noise spoilt the sound a bit but it does show interference-free flight which is what I wanted to see. Powering a large amp from the flight battery via a suitable regulator appears viable eliminating the need for a seperate battery and providing good "house-keeping" is employed in wiring everything up, interference is no more of a problem using a sound system than with normal electrics.

Next job is to get the right sounds coming out of the micro sound card. Can you help here John or Pete? What is the prop_2 used for? I still can't get proportional engine noise just constant acceleration above the dead band - am I doing something wrong? I'll hook it up to the computer in the next few days and see what I can do with it.

A suitable speaker is still needed. These heavier (527g vs 347g) ones I'm now using sound no different in fact a little quieter but then I'm not pushing them not wanting to blow any more. I've found mounting them into a built up fuselage covered with profilm covering really does make the whole thing one big speaker. Not sure how this will go in the Corsair with its solid, sealed speaker box but I'll find out.

A few more weeks to get my 65" electric Mustang back in the air and then I'll be back into the Corsair.

That voltage regulator circuit John is based on a few very common components. The regulator itself is a 7812 available in any electronics shop. It has a max input voltage of 35 volts for a regulated 12 volts out. The other transistor is a 2955 - very common in amps and should be equally easy to find. I can say it does work tho with no interference. As I build it into the Corsair I'll post pics.

Great to see all the input comming in here
Richard

Johnr
01-12-2006, 10:15 AM
Hi Richard,
Well done with that test flight, it is good that you have got it in the air with no interference especially with the voltage regulator. As you say it will reduce the weight.

As far as the programming is concerned, presumably you have followed the programming instructions for setting the dead band? Then to programme this with the auxiliary channel and then to set the top speed by getting the fast running engine sound as confirmation with the auxiliary channel?

The development micro uses the prop 2 plug for the auxiliary channel programming, but I note that Thomas has changed it the prop 3 for the auxiliary channel now.

Unfortunately the development Micro (as Thomas advises) is nothing like the production sound unit. It is totally scrambled now and fires the guns at random. However it was useful for proving that it does work in planes. It sounds like Thaustvedt is having a similar problem.

The speaker problem is the one to work on. The Visaton R10s is a cheap and powerful speaker and two are about right for acceptable sound output. But the 12 oz penalty is a bit on the high side for the smaller models of less than 70" wingspan.

I am about to test one Blaupunkt 0Dx 92 and compare with two Visaton R10s speakers. Just waiting for the club sound meter.

As far as the voltage regulator is concerned, did you wire it up exactly as the circuit? Can you post a picture of the regulator circuit?

Keep up the excellent progress and well done again for the test flight!

All the best,

John

tahustvedt
01-12-2006, 01:16 PM
I don't have the TBS Micro yet. I'm trying to complete the new Merlin sound set with Thomas but if I can program in my own sounds from the computer I think I'll just order one ASAP and add new sounds later if I come up with something better.

cyclops2
01-13-2006, 06:10 AM
Bundy. You might run into the same speaker problems I ran into.
I thought Hi- Fi speakers would be better. It turns out that the big speakers in G M cars were much more efficient than many expensive speakers. A Company stated that.:eek: I ran tests and he was right.
You have a great project. keep plugging away.

tahustvedt
01-13-2006, 01:51 PM
Because of the lower impedance maybe?

modeldesigns
01-13-2006, 05:00 PM
Hi Everyone,

The link should take you to short videos of John's HE111 flying from Raydon last Sunday. HE111 A is the take off, B,C, & D fly-bys and E the landing. Because John had installed the new high power amplifier into my Corsair the sound volume from the 111 is lower than it could be and my stills camera in video mode is probably not ideal for capturing the sound either.

http://www.putfile.com/modeldesigns

Enjoy your weekends,

Pete.

tahustvedt
01-13-2006, 06:56 PM
That was great! :) Lovely landing, it looked very real. The gunshot sounded very nice as well, but that's not an option with the TBS Micro I understand.

Thomas really liked the new sounds I sent him so I think I'll just order a unit and a cable and take it from there.

Bundy,
What happened to your B-25? Are you still going to install a sound system in it?

Bundy
01-14-2006, 12:24 AM
Hi All

After a few frustrating hours I've discovered the set-up instructions that came with my TBS unit have very little to do with the sound unit itself. This is in no way a criticism of the sound unit itself just the instructions supplied seem to be for a different breed.

For the benefit of those who are planning on getting the production TBS unit, here is what I found. There may well be other ways to configure it but this is what has got it all working for me.

The unit requires 2 channels - obviously throttle and another dedicated control channel. This control channel is in normal run mode when centred and the 'engine' has been started, up is engine start/stop and down is cannon sound on my card. The control channel from the receiver plugs into the Prop_3 input of the TBS and throttle to Prop_1. Prop_2 is left empty.

The instructions say 5 volt max input voltage - I connected up my normal 5 cell 6 volt receiver pack and got a puff of smoke from the TBS unit. It still appears to work after this but I now have a 5 volt regulator between the receiver and TBS unit. There is also a programmable dead band. This is a portion of the throttle stick's movement where only an idle sound is made regardless of where the throttle stick is in this dead zone. Once you move the throttle stick past the dead band normal proportional engine noise sounds right up to full bore.

Once the card is set-up it remembers the settings so this following sequence only has to be done once and not every time you start up.

1. Turn on transmitter and set throttle to min and control channel to midway centered position - a 3 position switch on your transmitter is ideal for this.

2. Turn on receiver which also powers up the TBS unit.

3. Bridge the LRN contacts of the TBS. This sets up the learn mode.

4. Move the throttle stick from min to the top of the desired dead band i.e. where you want normal engine running sounds to start.

5. Move the control channel to down and a short burst of acceleration noise is heard confirming the dead band position is stored. Return the control channel to centre.

6. Move the throttle stick to max and again move the control channel down and wait for short burst of full bore sound. Centre the control channel again and you are done.

In use you start the engine via the control channel being moved up giving the start-up sound, normal engine response then follows the throttle stick when above the dead band or idle while in the dead band and another flick of the control channel plays the shut down sound followed by silence. By flicking the control channel the other way the TBS plays the cannon fire sound while blanking out the engine noise.

I haven't tried to reprogram the TBS sounds yet but that will come.

Hope this saves others from a frustrating learning curve.

Richard

Bundy
01-14-2006, 12:49 AM
Tahustvedt - my electric Ziroli B25 has flown and flown extremely well but its size makes it hard to fly is regularly. I do most of my flying solo because we only have about 30 members in our club and loading and unloading a 101" 35lb plane by yourself is not easy. Also sound wasn't thought of when I first building this one and would not be easy to add it now. I have a smaller 90" 18 lb version on the drawing board now which will have sound built in from the start. I'm guessing it will be the end of the year before this one sees light under her wheels tho.

Great videos of the HE111 ! Any chance of a complete run down on the set up used - sound card, amp,speakers and watts, batteries, motors, wing span, weight etc? My flight test video is up at http://video.google.com/videoplay?docid=-2936190486501460302
but it is so wrong to have this sound coming from a plane like this.

Cyclops - Think you might have something here. I'm going to go back to my $6 car speakers unless somthing better comes along. Corsairs need nose weight anyway but not just for sack of it.

John - I tried to get some pics of the voltage regulator set up but it is mounted on 2 sides of black heat sink and they really didn't show much. As I build it into the Corsair over the next few weeks I'll get some more meaningful pics.

All good
Richard

modeldesigns
01-14-2006, 10:36 AM
Hi Richard,

Thanks for the info on setting-up the sound module, when i receive mine that will be most useful.

Good to see and hear a 2800hp Crackerjack taking the air(!) and pleased you are not experiencing interference.

I will let John give you the details of his superb HE111 but i have added the original video to the others on the Putfile site (the link to the same video posted in post 50 taking you to Google is incorrect).

http://www.putfile.com/modeldesigns

It was taken last year at Baldock so, again, it does not employ the high power amplifier. It also shows the Doodle Bug along side. If the videos are below 25Mb size you can upload them to Putfile and not have to wait for verification.

Pete.

tahustvedt
01-14-2006, 12:57 PM
I like putfile better than google video. If you want to keep the video on your harddrive after watching it on putfile you can look in your "C:\Documents and Settings\username\Local Settings\Temporary Internet Files" folder for them. They will have weird names but arrange by size and look for the right file extension, in this case MOV.

modeldesigns
01-16-2006, 08:44 AM
Hi tahustvedt,

Thanks for that. For anyone without the original i couldnt see how you could view the video again without downloading it each time, but that takes care of that. Three out of the five HE111 videos are now viewable off the Google site, in case anyone is having difficulty with Putfile:

http://video.google.com/videosearch?q=pete+nicholson

It's off topic, but does anyone know of free software for basic video editing (like joining videos together, adding titles etc.)...here is the rub, software to run with Windows 98 SE?!

Pete.

Johnr
01-16-2006, 09:55 AM
Hi Richard and all,
Well done for figuring out the Micro programming and writing it all down. It would help Thomas and other customers if you e mailed him your set-up instructions for him to include in his information. Congrats to Pete as well for posting the Video clips, it was a very dark day. Glad you liked it Tahustvedt, the HE111 is a *****cat to fly and it could have been slower on landing but there was a cross wind that day.

Richard, the HE111 is 100" wingspan scratch built. My friend Trevor and I built two and the plan and vacuform moulds were sent to Traplet, so it is available. It airlaunches the V1 from about 500 ft and this three channel rocket ship is flown down (by someone else!) It has a small ducted fan for maintaining level flight for about three minutes. All up weight with V1 and sound etc is about 16lbs.

The HE111 is now powered by 2 AXI 4130/16 outrunners driving 15x10 APCe props. Each motor is driven by 14 - 2.4ah old nicads to give a maximum flying time of about 10 minutes. Retracts are home built and based on large Robart air cylinders, which help to give it air suspension.

The sound card is the TSB4 and two 20w(peak) Benedini ampliers each powering a Visaton R10s speaker mounted in the underside of the wing. A 12v 10cell 700mah Nimh pack powers the sound unit and amplifier for about 14 minutes. The sound unit is controlled by two separate miniature servos switching microswitches for start/stop and guns etc.

As posted before, the development Micro and 2x40w amplifier has been fitted in the HE111 and driven by the same 12v battery to produce a much louder sound. The new amplifier is so much better and lighter as well. The Video clip sound is from the smaller amplifiers as the Micro and larger amp were then in Pete's Corsair.

The HE111 has had nearly 100 flights now although it was virtually written off in 2003. Since the rebuild it has had well over 30 flights with sound and no problems. The crash was not found to be sound related. I think it was radar interference form the nearby control tower.

Thanks Richard for trying to photgraph the power supply unit. Look forward to a picture when you get a chance. Did you make is exactly as the wiring diagram you posted and is there much heat dissipated?

Like the B25 pics!

All the best,

John

Leo
01-16-2006, 08:19 PM
It's off topic, but does anyone know of free software for basic video editing (like joining videos together, adding titles etc.)...here is the rub, software to run with Windows 98 SE?!

Pete.

Hi Pete,
I have used the free trial versions of the Womble Video Wizard and the Video ReDo for editing video .mpeg files on my Win 98 based system.

http://womble.com/products/
http://www.videoredo.com/?src=VRD2004-09-08

Hope this helps
/Leo

tahustvedt
01-17-2006, 09:46 PM
My spit arrive today and the radiator covers are huge! The width at the widest spot is 12 cm.

Bundy
01-19-2006, 12:21 AM
Hi All

Thanks for the He111 details John. 16 lb for 100" is VERY impressive! What construction methods did you use to bring it in so light? My 101" Ziroli B-25 uses tradional balsa/ply construction 1/8" planking and skinning, glass and Flight-Metal and comes in just over 35 lb AUW. I could save a little by not having 4P lipos for 20+ mins of flight but I've never heard of one of these Ziroli B-25s coming in under 30 lb even in a bare bones version with no gear doors etc.

I really love this plane but have to make it more practical. I'm looking at either a smaller version or going the foam/brown paper method which Chris Gold has shown to be perfectly workable at these sizes. Do you think 2 sound cards would have any advantages for a twin engined plane or just one programed with twin engine sound?

I've been working with Thomas trying to help smooth out the instruction manual. It really shouldn't take much and the bottom line is the sound card does all it should.

Any pics of the Spit tahustvedt?

Richard

Johnr
01-19-2006, 10:12 AM
Hi Richard and all,
Glad you are working with Thomas to get the instruction wording a bit better, it will be really helpful as we found it a bit confusing as well.

I think that a twin can have two micros and I was working on that last month. So one engine can go through the start procedure, and then the other. The problem is with the transmitter as I think you need three spare channels with a programmable transmitter. I have the Futaba 9 ch set and it is possible to programme a three-position switch to give the throttle stick command of the LH, RH or both engines. The way to do it is described on the Futaba web site. I wanted to do it for the 93" Beaufighter, but I only have two spare channels as the bomb drop uses channel no 7. I will do it on the my next model (100" DH Hornet) which will not have a use for Ch 7. So the answer is yes I think it can be done.

The HE111 was designed specifically for electric flight and substantially weaker engines than the AXIs that we are using now. I also try to aim for a wing loading of less than 2lb/sq ft to give benign flying characteristics. The Ziroli design is probably for large I/C engines and the Americans do like to pile on thick planking. The HE111 uses spaced out 2mm lite ply formers and 1/16" sheeting throughout. This is fine on the wing but can give a 'hungry horse' effect on the fuselage. The orginal HE111 airframe weight came out to about 8lb with U/C. On my 93" Beaufighter (16 1/2lb auw) and also on the present design and build of the 100" dh 103 Hornet I now use 3/32" sheeting on the fuselage - like the great Brian Taylor. The Beau has just been been re-engined with AXI 4130/16s and is now overpowered. Hope to fit sound on this soon but cannot find a decent sound file of a B25 or similar. Does anyone have the 'round sound vol one' CD?

Hi Thaustvedt glad you got the Spit, yes some pictures would be good.

My speakers tests are waiting for a sound meter and the club meter is lost but about to be replaced, so should have some results soon.

All the best,

John

tahustvedt
01-19-2006, 03:41 PM
The kit weight is 3620 g, and I estimate the weight of everything I add to it to around 1590 g so the total should end up around 5210 g without the sound system. This is lighter than with glow power. The kit weight also includes some glow stuff I won't be using. The White/orange Velox you see in the picture below also ended up weighing less than it would with glow power and it has the same power system I'll be using. The kit includes a complete air-retract system and all hardware.

I got a sound demo from Benedini today with the sounds I sent him and it sounded very good. I'm going to pay him today and then I might have the system by the time I get back from a two week business trip I'm leaving for this sunday.

Bundy
01-22-2006, 08:30 AM
HI John

Thanks for putting all those figures together. I'm madly number crunching now and I reckon I can build a 101" B-25 under 25lb, use only 4130/20 AXI motors and break it down for transport so it will be a one person job.

I just need more hours in the day to build it all or maybe start a caffeine habit!

Thanks for the pic tahustvedt. I'm sure you'll be more than pleased with the Benedini sound card. Be sure to keep us up to date with your progress.

Richard

modeldesigns
01-24-2006, 05:04 PM
Hi Leo,

Many thanks for the info on video editing software, i will look into it soon.

My radial engine sound module and amplifier arrived from Germany on Monday (thanks Thomas). I now have them installed in my H9 Corsair and the sound is working well. I have posted video of the Corsair starting and shutting down. I had to use two videos since Putfile does not allow files of over 25Mb.

http://www.putfile.com/modeldesigns

The photos show the installation. To power the speakers i am using a 3S 1600mAh LiPo pack that is strapped to the wing bolt plate in order to preserve the balance point - there is quite a lot going on in the nose!

The ESC and UBECS are together on the underside and the sound electronics on the upper side. Typical of a radial cowled prototype, you have great access to everything by slipping off the cowling.

The plan now is to get some video of it flying.

Pete.

modeldesigns
01-25-2006, 09:27 AM
Hi Everyone,

For anyone contemptlating trying a similar installation, below are pics of the Benedini amplifier and sound module and my wiring loom. I requested my module to be programmed as auto start. You do not require an additional channel for operation, it is all worked in parallel with the throttle and the sound is activated by the stick position. The shut down is automatic following a 20 second period of closed throttle. The two sockets exiting the amplifier go to the speakers and you have to provide and build the wiring loom. All flight servos and the Rx power plug in as normal.

Against the sound module is my bridgeing tool used to bridge two lands in the pc board to 'teach' the module. It's simply two pins pushed into a piece of balsawood soldered together at the other end. The pins enter the two holes in the board and ensure a good contact.

Pete.

modeldesigns
01-25-2006, 09:28 AM
Hi Everyone,

For anyone contemptlating trying a similar installation, below are pics of the Benedini amplifier and sound module and my wiring loom. I requested my module to be programmed as auto start. You do not require an additional channel for operation, it is all worked in parallel with the throttle and the sound is activated by the stick position. The shut down is automatic following a 20 second period of closed throttle. The two sockets exiting the amplifier go to the speakers and you have to provide and build the wiring loom. All flight servos and the Rx power plug in as normal.

Against the sound module is my bridgeing tool used to bridge two lands in the pc board to 'teach' the module. It's simply two pins pushed into a piece of balsawood soldered together at the other end. The pins enter the two holes in the board and ensure a good contact.

Pete.

Johnr
01-25-2006, 09:50 AM
Hi Pete,
Well done that man, the results are very good. Now what about the other 43 million other Hanger 9 planes you have, you can't leave them in a quiet state now can you? I think that you should have a squadron of planes ticking over just in case a 109 is out there somewhere!

Anyway, congratulations on the success, and we look forward to the flight video.

Hi Bundy, yes the B25 would be really good with sound, but why 4130/20 and not 4130/16s? That is what Pete and I use and then you only need 6s thus saving some more weight. At 50 amps you will get a ten minute flight and at 40 amps much longer. My Beaufighter is overpowered with the 4130/16s and still running on Nicads - remember them?

Hi Taustvedt, like the Spitfire, that should take all of a week to complete!

The speaker test rig awaits the sound meter which is on order. The wife will want her waste paper bin back soon.

All the best,

John

All the best,

John

modeldesigns
01-25-2006, 10:38 AM
Hi John,

It would be good to get sound into the other models. If your excellent experiments with different speakers confirm only a single, high power speaker will do the business then, together with a BEC device for the power, it should make it more than viable for models of H9 size.

If all else fails then we just need to build larger for the warbird fighters, i am convinced sufficient sound volume is there already. Perhaps 1/5th scale? The additional 1-1/4lb weight of the sound hardware would be easy to accomodate whilst maintaining plenty of performance.

Pete.

Gordon
01-30-2006, 08:10 AM
Hi Pete

The Corsair sounds tremendous. Have you flown it yet? If you still need video you know where there's a camcorder always ready and waiting ;)

Cheers

Gorodn

modeldesigns
01-30-2006, 04:26 PM
Hi Gordon,

Yes, i am well pleased with the sound in the Corsair and would love you to here it for real.

That is a very generous offer, THANKS.

I have not flown yet with my own sound hardware installed and with the radial engine simulation. It's all ready, but the weather beat me this weekend.

To bring a servicelable aircraft, an excellent site, the weather AND a video camera man together is proving difficult, so i will take you up on your offer if i may. I will call you this evening.

Cheers,

Pete.

Bundy
01-30-2006, 08:45 PM
Hi Everybody

Great work there Pete getting all that to fit in the Corsair and was so interesting to see the auto-start mode working. I haven't been able to get this to work on mine.

I'm in two minds which way to go with it. Auto-start's simplicity is seductive but with only one channel ( since throttle is there anyway ) you can have full control over the sound as well as gun fire which I think would be really effective. I'm using a 9 channel JR transmitter - 6 basic functions, 7th is canopy opening, 8th is cowl flaps and 9 can be sound or tail hook. I think sound might win.

I've now substantial finished my new P-51 and am now focused back on the Corsair. I'm building a 12 voltage regulator for the amp and a 5 volt regulator for the TBS into the amp's heatsink and mounting the whole package mid fuselage and ducting air from the oil coolers over it and out the scale engine flap to keep it all cool. Pics in a few days all going well.

Not being a sound buff, how does the sound from a 2 X 40 watt amp compare with a 70 watt amp? Are they the same or is it not that simple? How many amps does the 2 X 40 watt amp draw?

On page 11 of the TBS manual there is a note about a link in some amps connecting all the earths ( receiver, sound card and amp) together. Is this a good or bad thing? My trails so far have had the big common earth and all seems OK.

Looking forward to the flight video Pete - hope all goes well :)

Richard

Bundy
01-30-2006, 08:50 PM
Just a quickie

When evalulating sound performance, we have been looking at amp power and speaker type and number but how important is the design of the box we put it in? http://www.termpro.com/articles/buildbox.html is saying the volume of the sealed box plays a big role in how it will ultimately sound.

ciao

Richard

Johnr
01-31-2006, 11:00 AM
Hello Richard and all,
I do not think there is a facility for a 'special sound' if the Micro is programmed to not use an auxiliary channel. I can't comment about a common earth, but I think Thomas said that it was not a good idea. We have not commoned ours up and things work fine with them separate.

I have now tested the 2x40w amplifier with the Visatons and the Blaupunkt speakers. With one speaker on each channel then the total current is less than 3 amps at 12v on both setups. I know that if the Visatons R10s are driven much harder they will blow. I also know that the input power demand does not seem to equate with the rated output of 2x40w amplifier, especialy as audio amplifiers are not that efficient. That is obvious from the heat that they emit.

The two Blaupunkts emit slightly less sound, but may have the capability to be driven harder.

At 1metre (inside the garage) the sound output was 100dBa for the two Visatons.

I cannot get anything like that output from the Oz amp. Maybe I made it incorrectly, but as it is so big and heavy I prefer the new Benedini 2x40w amp. Thomas is now developing a 30watt 30v amplifier and I hope to try it soon. This should eliminate the battery (or voltage regulator) so long as the sound output is good.

Keep up the good work with the voltage regulator Richard, was there a problem with the first one that you made? Can you publish details?

As far as the sound box is concerned it seems that the bigger the box then the better the base response. I have just fitted a couple of Visatons in the U/S of the wing of the Beaufighter and the cavity is quite large between the spars. As you saw, Pete's installation of the speakers in the cowl is very neat and the speakers cannot be seen. I just wish I had the space in the Beau.

In theory it should be possible to get the additional weight of the sound system to less than 0.5kg for the smaller models of around 2m wingspan if a single small speaker can be driven really hard.

Hi Thaustvedt, I have just sent Thomas some good Merlin engine sound files which he might be able to use for you.

All the best,

John

modeldesigns
01-31-2006, 11:56 AM
Hi Richard,

I only have a six function Tx and Ch 6 is a rotary knob, which is difficult to use at the best of times. When John loaned me his module we did manage to get it working off the rotary knob but idealy it needed a three position toggle switch. As it turned out, in auto start i can work everything off the throttle stick and its trim and this makes things so much easier in my opinion, so i am happy. It would have been great to have the choice of additional sounds but i could see it would be very difficult to activate them off the rotary knob whilst flying. All i am wanting to achieve is a realistic engine sound 'presence', which a judge remarked was missing when i flew the electrified Corsair in a BMFA Flying Only competition.

I am not qualified to answer some of the questions you are asking Richard but re the current feeding the two 4" Visaton speakers, at maximum volume the Wattmeter (placed between the 3S pack and the amlpifier) reads 2.7A/31W.

Each of my two speakers sit in an enclosed volume of 19sq ins each. The table of sound box volumes in the link above only go down to 6" size speakers so i do not know if i am near the ideal or not, i supsect not.

Flying video to follow soon hopefully,

Pete.

Bundy
02-02-2006, 06:07 AM
Hi Guys

I've managed to mount all the sound parts into the Corsair and see what it sounds like. Video is at http://media.putfile.com/Corsair-Sound-Trial
It was done with my original $6 car speaker which I smoked a few weeks ago but it still works somewhat. I only cranked the amp to 3 amps with this speaker because anymore didn't make for any more volume just amps but it gives some idea I've where I'm heading. The prop in the video is a 20" X 10" and even on one of Gordon's soft mounts still makes a lot of noise. There is even a burst or two of the gunfire in there. It sounds like Thomas's 2 X 40 watt amp in to 2 speakers is making roughly the same noise as one 70 watt amp driving one speaker both at 12 volt and 3 amps. We still need a small, light speaker that can handle been driven very hard.

The complete sound unit consisting of amp, TBS card 12 volt/6amp voltage regulator, 5 volt regulator and heat sink weighs 175 grams with the speaker another 300 grams. A regulator with heat sink is way lighter than even a 3S2P lipo. This sound 'block' is self contained - there is a 20volt input, a lead to the receiver with 2 plugs - throttle and control channel and a speaker output. As set up here the speaker is in a 190 sq" sealed box. I can't see why the whole fuselage couldn't be used as speaker enclosure getting close the ideal figures.

I've been toying with a 40volt to 12 volt regulator but with out much success - plenty of smoke tho. I just can't find components rated this high that work at the amps I need. A 30 volt amp is getting closer but to fly this plane I need a 10S lipo pack which when fresh is touching 42 volts. At a max of around 50 amps that is giving 2000 watts to fly 18lb of warbird fighter which is about right. Presently I'm tapping one of the lipo packs to give me 20 volts for the amp.

I'm about to fire up the hot wire cutter and see if I can't make a lighter version of this Corsair. I think it may be possible to even fit a 6" speaker in if I make the whole fuselage one big sealed speaker box.

There is certainly no shortage of ideas to try.

Richard

modeldesigns
02-02-2006, 10:01 AM
Hi Richard,

Absolutely amazing pioneering work in some fabulous looking wood and metalwork. Well done.

I hear what you mean about the prop and motor noise drowning out the engine sound above idle. I have not had the chance to get my Corsair into the air again but in the one flight with John at Raydon, you could certainly hear the engine sound well (even though it was a twin Merlin!) so i am confident we have sufficient volume, at least for the motor/prop i am flying on.

I like your idea of a sound 'block' and it keeps things tidy. Is the hole underneath the amplifier your outlet for the sound?

Thanks for the video and all the best for future experiments!

Pete.

Johnr
02-02-2006, 05:01 PM
Hi Richard,
Well done with all the progress, that is a good looking plane. What AXI motor is it?

Do you have access to a sound meter? If you can do a test we can compare sound levels. I did mine inside (as we don't have that bright light in the sky like you do) and got 99-100dBa at 1m distance from the two 4" Visaton R10s speakers and the 2x40w amp at 2.5a and 12v. The Blaupunkt speakers gave less but I am waiting to crank them up with the higher voltage amplifier.

All the best,

John

Bundy
02-03-2006, 09:07 AM
Hi Guys

I've done some sketching and I can fit a 6" speaker in the cowl of a 1/6th scale Corsair. After a bit of hunting around the local car stero shop and trying explain what I wanted a speaker for I now have a pair of 6" Blaupunkt slimline speakers. Cost was $97 AUD for the pair, 210 watt max and 70 watt RMS and best of all 276 grams each which is lighter than the 4" speaker I've been using.

I can't explain why but it draws half the amps the 4" speaker does on the same settings and there is plenty of sound there on only 2.5 amps and boy does it sound SO much better! Hope to get into town tomorrow John and see if I can get a sound meter and see if we can start quantifying what we are hearing.

The AXI motor is a 5330/18 and a 90 amp Jetti ESC. My current thinking is to mount the 6" speaker facing foward and mount this motor in front of it. Not sure if there are any problems looming here with magnetism issues or if the motor will blank out some sound but the fit is too tempting not to try it. I've never done any building with foam before thinking it wasn't 'true' building but once all the templates are sorted out, it is very quick way to build airframes.

Interesting point about what judges are looking for to make a plane 'sound right'. My wife has very little interest in model planes although she has learnt to fly. This is good because I can bouce ideas off her from a totally detached viewpoint. Her comment on the Corsair was yes it sounds just like a real one but it is not the sound you would expect from a 1/6 scale Corsair. What would a 1/6th scale R-2800 sound like?

We had a real airshow here last year with a Super Constellation there. We were standing about 100 meters away as it rotated on take-off with all 72 cylinders on full song. Even if it were possible to recreate this sound ( and feeling) there is no question that a model making this noise would be totally wrong. Perhaps once speakers, amps and speaker boxes are sorted, the actual sound recordings might need some tweaking. I'm not sure how or in which direction - again what should a 1/6th R-2800 really sound like?

I'll try and get some get some dB figures in the next few days - that'll be interesting.

Richard

tahustvedt
02-03-2006, 02:27 PM
Back from the Lynx course now. Learnt a lot and ready to start on my Spit.

Bundy. That Corsair-video was great. :) The prop-sound sound be greatly reduced in flight when the prop profile AOA is reduced.

Bundy
02-05-2006, 08:49 PM
HI All and welcome back Tahustvedt

Attached are some pics of how I set up for this sound test. Sorry abhout the bright sunlight!

First test show 102 dB from this Blaupunkt ODc 650E 6" ( http://www.blaupunkt.com.au/7606327000_main.asp ) speaker mounted in a 140 cubic inch vented box ( an old facum forming box that turned out too small) drawing 2.3 amps, 12 volts to the amp with the sound meter 1 meter away all inside a shed with doors open.

Obviously room to crank it up but 102 dB is plenty load enough for now - this was an ear muff job. Big improvment with this speaker is the clarity of the sound - it is just so much cleaner sound. No hiss and crackle I got with the 4" $6 speacials.

Now to biuld a new Cosair to put it in. Flying by Easter??

Richard

Johnr
02-06-2006, 04:08 PM
Hi Richard and all,
Oh, it is sunlight is it? You will have to tell us more about that as we have not seen that for years it seems. Maybe a few days, but it is very dreary here.

Those are very interesting figures you are getting for the sound. It is all beginning to tie together. You are now consuming the same electrical power as us and getting a bit more sound output, presumably because of the larger more efficient speaker. Very good!

At 276 grammes that is too much for us but it shows what can be done. I am hoping that the 89mm Blaupunkt speaker at 150 grammes can be cranked up to nearly 100dba if the voltage is increased. (Either that or a very expensive puff of smoke). That could also eliminate the sound battery or voltage regulator. I have ordered some Micro circuits and amplifiers for the ME109 and the Beaufighter but Thomas is out of stock at the moment. The 109 inertia starter sounds gorgeous.

My wife thinks I am a sad git when I talk to her about electric sound files, so no change there, but all I can say to your wife's comments are that when Pete was flying his Corsair in the murk, on the back straight, the impression was that it really was a full size Corsair. It was very difficult to see the model detail and the sound was just right. Then my very small brain did a mental flick to put me in the middle of an airshow. You won't get this in Australia because of that bright light in the sky.

Have you got your Micro yet Thausvedt? I have sent Thomas some good Merlin engine start-up files that he could use for your Spit sound.

All the best,

John

tahustvedt
02-06-2006, 04:50 PM
I don't have my Micro yet. I'm in no rush as it will take a while before the Spit is ready, and I would like the sounds to be as good as possible.

There's plenty of room for a pair of 4" speakers in the radiator covers if I mount the flap servos close to the trailing edge of the wing. Do I need to seal the speaker cavity in any way or should I try to let the whole wing act as a box? I figured I'd try that first.

Johnr
02-07-2006, 09:15 AM
Hi Thaustvedt,
I would think that it would be fine to leave the wing as a sounding box so long as you keep the speaker sealed into the box. I am no sound engineer, but as I understand it a sound wave from the back of the speaker can cancel out the one from the front of the speaker unless it is designed correctly. I was also advised that any horn loading on the front can help. This can be like a megaphone tube on the front. I know this would look silly, but deflectors in the radiators might help.

Make sure the ribs are glued on well to the surface sheeting as the sound managed to break some of my joints on the HE111.

All the best,

John

Bundy
02-08-2006, 09:04 AM
Hi All

A few more results from playing around...

With the 6" Blaupunkt mounted in the unsealed old vacuum forming box, it gives around 102-103 dB at one meter and 2.3 amps. When the box is sealed this dB reading drops by about 0.5dB repeatedly so tahustvedt I agree with John - seal the front of the speaker and leave what is behind as a sounding box. Taking the speaker out of the box altogether drops the dB reading down to 95dB.

The dB reading in front of the box's vent - 90 degrees to the speaker itself gave a reading of 100 dB at 1 metre. Significant sound seems to come from behind the speaker as well. Like John says - build it strong.

Mounting an AXI 5330 on a 50mm aluminium mount 20mm directly in front of the speaker had no effect whatever on the dB reading. The motor's magnets don't seem to effect the speaker at all.

Using the old 4" speakers - one gave a dB reading of 95 and two only increased this to 96dB. More work is needed here but perhaps using one bigger speaker if physically possible would be more efficient than two smaller ones?? The area of a 6" speaker is bigger than two 4" speakers and the 6" would be lighter than two 4".

And don't be too worried about being called a 'sad git' John. Far better to be a sad git into his sound waves than a boring old git with no interest in anything :)

Richard

Johnr
02-08-2006, 10:49 AM
Hi Richard and all,
Yes, you have put your finger on it. If you want the best sound and can fit a large speaker then that is the way to go. Two speakers each giving out 97dBa each only make 100dBa total, to then increase the sound level to 103dBa one then needs double again - ie 4 speakers! The fact that you have achieved 102/3dBa on 2.3amps is excellent.

However, I do not think that most people could find the space for a 6" speaker, and two 4" speakers are difficult enough. If I fitted one 6" speaker in a wing then I think I would only be flying circuits in one direction.

We have a problem with conflicting requirements and the best way is to get lots of options to sort it. I think the smaller planes will have to compromise with smaller speakers and take the loss of sound output as a consequence.

By the way Richard, we went to look for a house for my daughter at the weekend. As prices are so high we even looked at a house that had had squatters in it. There were heaps of rubbish inside and guess what - two model aircraft hanging from the ceiling. The wife rests here case!

All the best,

John

old git
02-08-2006, 10:02 PM
Just found the link
http://electronics.howstuffworks.com/framed.htm?parent=ces2004.htm&url=http://www.s3isound.com/
It was at the Sceince Channel on Sat. Looks cool, but I don't know if it will help or not.

I agree the sound of a weed eater or worse still a glowplug motor are not the most realistic. More of this when you electricians get it sorted. Most of the noise from a model purports to come from the airframe acting as a sounding board.

I'd like to follow you when it is sorted out. I haven't yet come to grips with lithium batteries.



Aren't wheels great?

No matter how badly you kill an aircraft, the wheels are always okay!

(With thanks to Andy Ross)



old git

tahustvedt
02-08-2006, 10:29 PM
I installed Kavan rubber mounts for the motor on my spitfire in an attempt to reduce the resonance howling, but I haven't tried running the motor yet. I have to get it up on its wheels before I try it out.

old git
02-09-2006, 01:11 AM
Hi Richard and all,

However, I do not think that most people could find the space for a 6" speaker, and two 4" speakers are difficult enough. If I fitted one 6" speaker in a wing then I think I would only be flying circuits in one direction.

John

All I was wondering was if the airframe vibration results in the propagation of noise maybe a couple of speaker solenoids in the wings would help the sirframe to act as the diaphragm of a speaker.

old git


Aren't wheels great?
No matter how badly you kill an aircraft, the wheels are always okay!
(With thanks to Andy Ross)

tahustvedt
02-18-2006, 02:03 PM
I got my stuff today. I'm missing speakers but I have a few old PC-speakers I can use to play with it while I try out sounds.

Pete, I read your article on the P-47 in QEFI. You sure do a lot of warbirds. :)

I haven't finished my Spit yet but it's getting there. Motor is installed. I just have to install servos in the fuselage, make a battery box, and join the wing basically. Well, maybe "just" wasn't the right word.

tahustvedt
02-19-2006, 12:24 PM
I have a few questions.

Does the TBS Micro need 5V power when it's connected to the PC for programming? It doesn't work like the manual describes when I just connect it without power. I don't want to damage it. I connected the programming adapter between the TBS and PC with the brown wire in the corner of the PCB, started HT using the included script and hold the button but nothing is happening.

Can the amplifier be connected directly to the LS points? I noticed Pete's unit has one speaker wire soldered to a point on the opposide side of the PCB while on mine bopth wires are soldered at "LS".

On the input side of the 2x40W amp there are three pins. NF input 1, NF input 2 and "Masse". Is "Masse" ground?

tahustvedt
02-19-2006, 01:35 PM
I managed to get it to work now. I connected a 1S lipo as a power source andthen it would enter programming mode. I set it up in autostart and tried it with a little speaker connected directly to the TBS micro. It works. :)

Programming with the computer is easier than I imagined, once I figured out how to get it to start.

My TBS Micro gets pretty hot when connected to my 5V UBEC, even when it's not playing any sounds. Is that normal?

Johnr
02-20-2006, 11:22 AM
Hi Tahustvedt,
Well done for mastering the programming. I have not noticed that the Micro gets hot even when not playing any sounds. Have you checked the voltage on your UBEC? It could be that it is the integral 1 watt amplifier on the Micro that is getting warm.

Tha small lead on The Pete's Corsair Micro was the flying lead that I soldered to get into the programming mode by touching it to the joint beside. You are right that it has nothing to do with the amplifier connections.

Can you tell us more about what you did to programme the unit via the PC? Did you get another programing lead?

All the best,

John

tahustvedt
02-20-2006, 12:55 PM
I bought the serial programming lead from Thomas when I bought the TBS. After connecting the lead between the PC and TBS Micro I connected a single cell Li-Po battery (4,2 V) to the throttle channel of the TBS. Then I started HyperTerminal on the PC and pressed and held the button on the programming lead until it had beeped twice. The menu then appeared in HyperTerminal. It's really easy to navigate, just press the number of the menu you want to enter, and press Enter to go to the next line or -/+ to change a value. ESC returns to main menu or exits.

I measured my UBEC and the output voltage is 5,04 V.

modeldesigns
02-20-2006, 01:43 PM
Hi Tahustvedt and all,

LOL, yes, warbirds are my favourite. I am following your thread on the the Spitfire build on E Zone and the additional detail you have added looks very impressive. Good luck with the project.

On the Saturday just past i finally managed to bring everything together and the Corsair has now flown with a radial engine sound simulation. I owe a very big THANKS to John for all his expertise and encouragement and to Gordon for braving the cold and getting the video. You can see the first flight off here:

http://www.putfile.com/modeldesigns

More video is to follow soon.

Assuming it is possible, in my opinion the sound volume needs to be reversed i.e. the high power engine sound volume level should replace the engine idle sound volume level and vice/versa. Even as it is, i can see the potential for realism in flight. In the part of the recording showing the cowl coming off, when you hear the normal two stroke engines in the background, it really brings it home. And don't forget, if required, the model can be flown without any sound by simply not turning the speaker circuit on.

The flying weight of the Corsair is now 10-1/4lb compared to its usual 9lb. I am flying the model a little too fast to be realistic but i wanted to be safe operating at this higher wing loading and i am sure with practice i can cruise around at a lower airspeed. The real answer, though, is to now place the same sound hardware in a larger airframe...and add brakes and smoke on startup!

Keep up the good work everyone, IT IS going to happen!

Pete.

ps. The horrible scraping noise when the model is taxiing is the hard plastic tail wheel. I replace the supplied soft foam ones as they tend to flatten off with time but for operating off of tarmac with sound, i need to change them back.

Johnr
02-20-2006, 02:25 PM
Well done Pete,
That really is excellent progress with super flying (as usual), and every flight that is managed without problems is another to prove the reliability and airworthiness of the system.

Next year reserve your seat at the Baftas Gordon for the super video clip, and as for the acceptance speech for the best director, I guess you had better start jotting down some notes!

Thanks for the information about the programming lead Thausdvedt, I think I will have to try a lead to see if that helps with changing some options if required.

Richard are you still out there sunning yourself in Brissy? How about some more pictures of your Corsair build with that fantastic flying field?

All the best,

John

Gordon
02-20-2006, 02:42 PM
Hi Guys

This project is getting better and better!

I must say that I'm bitterly disappointed with the amount of wind noise on the video. I bought an external directional mike costing 100 quid for the camcorder with the intention of cutting out camera drive noise, and enhancing sound reception from a distance. I only found out after watching the videos the day after we flew that adding the external mike switches off the wind cancellation in the camcorder. There was next to no wind at all, but what little there was sounds like a gale on the video. So much for Canon quality!

So it looks as if the external mike will stay in its box and I'll have to put up with motor noise.

Even so, it doesn't detract from the success of the sound project at all. Pete's super-smooth flying was a joy to video, and the engine sound was fantastic.

To get the best effect on your PC, turn up the volumes to max on the speakers and sound card. Then control the sound level output by left-click and hold on the putfile volume slider, decreasing volume when the plane is on the ground, and increasing it to max when it's in the air.

Cheers

Gordon

Bigplumbs
02-20-2006, 09:18 PM
Hey Pete now you have got me reading these boards as well

www.densplanes.co.uk

modeldesigns
02-20-2006, 09:26 PM
Hi Bigplumbs,

That's the trouble, it's too easy to spend ALL your time on here and not get on with the practical!

Good that we can share ideas though.

Pete.

Bigplumbs
02-20-2006, 09:30 PM
I know but I am waiting for some glue to dry on my H9 Mustang...... But shush I can't mention it in this forum................. You know why.

modeldesigns
02-20-2006, 11:14 PM
Hi Bigplumbs,

IC(!), i won't tell anyone then...

Pete.

old git
02-21-2006, 12:48 AM
Hi all,

I last built a model in the 70s and now retired am back to the fold. Things have changed beyond all recognition. I thought I had kept in touch with modelling by buying the occasional magazine and now retired for a few years, decided to build again. I think the video of the Corsair is a tour de force, so many different branches of technology coming together to make a film that doesn't need special effects to look real. Congratulations to all involved.

I previously made a comment about using the airframe (wing skin perhaps) as a substitute speaker cone and thereby saving weight but maybe I was misunderstood. I am among the many, being without special knowledge of the subject of speaker design but would like to understand why the idea is not practical if that is the case.

old git

Aren't wheels great?

No matter how badly you kill an aircraft, the wheels are always okay!

(With thanks to Andy Ross)

Johnr
02-21-2006, 08:58 AM
Hello Andy,
It has been suggested before to force the wing skin to vibrate and use that as the sounding board instead of the speaker. In fact there are some commercial (NXU I think) flat board heavy speakers that use this same method. This principle does happen on the model as a reaction to the speaker pulsing the air in the wing. If just a solenoid were used then I think it could be used to produce some sound, but probabaly not enough, and probably not the right quality of sound. When I see how hard these poor little 4" speakers are working, and the flexing amplitude of the cone to move the air to make the sound, I think it would be difficult to get the wing skin to compete in a similar fashion. I hope someone proves me wrong though!

Hello Dennis, I hope you wash your hands before coming on this site. We don't want methanol streaks here!

All the best,

John

All the best,

John

modeldesigns
02-21-2006, 10:31 AM
Hi Everyone,

I have now posted a video of the Corsair's 2nd flight with sound. Thanks once again to Gordon for the excellent film work.

http://www.putfile.com/modeldesigns

I must have set the props tick over a little higher this time since i got the model moving on low idle sound. In 'Auto Start' mode, which is what i have my sound module on, the sound shuts down after 20s of idle and in the film you can here the sound 'cough' as i just caught it before i turned into wind for the take off. That would have sent a chill through any full size pilot as he was about to trust his life on the motor in front of him!

The Axi 4130/16 on TP 6Ah 6S ProLites and a 16" Pattern prop in the calm air gave even a 15% overweight Corsair a carrier take off - very impressive. The total filming time included 5mins of warbird flying and i used 2.5Ah from the flight cells and 0.4Ah from the 1600mAh 3S LiPo amplifier battery. I should still have enough capacity for a safe 10min warbird flight, even at the higer flying weight.

I must find my Corsair manual and read-up on stall turns...room for improvement there! LOL.

Pete.

inedesca
02-23-2006, 08:17 PM
Could anyone rather design a whistle or siren which might resemeble the engines sound?
I mean, maybe some kind of whistle taking advantage of wind speed and resonant chamber from the wing or fuselage.
Somebody which knows about whistle or siren design?

eamrc
02-27-2006, 05:51 AM
AWESOME GUYS I JUST FOUND THIS THREAD !! I have got to have one of these for my B-17, also I am an audi buff from way back, I have a recording studio at my house, used to do P.A. work for concerts so this really stokes me to find ways to maximize our db output. Just sent an E-mail to get a sound module so I am in !

Johnr
02-27-2006, 10:29 AM
Welcome Eamrc,
Your the sort of guy we need, and audio expert! We need top get more research done on small lightweight speakers that throw our large amounts of sound (100dBa+ at 1 metre). Can you suggest any improvements on the Visaton or Blaupunkt versions as mentioned in this thread? We really need more than 30w rms from less than 150 grammes.
All the best,
John

CorsairJock
02-27-2006, 02:07 PM
Hi Guys (and Gals?),
I just started a thread in the RC Universe/ Warbird forum which contains links to the 2nd flight, and this thread, so 'traffic' might be picking up a little bit here.

Here is link to that thread:

http://www.rcuniverse.com/forum/m_3963203/tm.htm

That startup/ idle sound is GREAT, it that from the sound file that I sent in? I sure wish I could put one of these in my H-9 Corsair, but I can't afford it.

Gordon
02-27-2006, 05:22 PM
Hi all
I shot the video. To get the best from the sound you should left click and hold the volume control, and set it to low for the idle and taxi phases, and open up the volume to full during take-off and leave it there during flight. Granted it's still not perfect, but it is better.

The main problem with the video is the wind noise. I'd fitted a $$$$ Canon DM50 shotgun mike to the Canon camcorder for the first time, thinking it would improve the sound. What I hadn't noticed in the instructions is that fitting the external mike shuts off the wind cancellation feature, which is why there's a lot of wind roar during the flight.

So the mike was a big waste of money as I bought it especially for this kind of filming :(

Cheers

Gordon

modeldesigns
02-27-2006, 05:35 PM
Hi CorsairJock,

I do not know if the radial engine sound is from a sound file you sent in (to Benedini?). I am using it as it was supplied and it sounds fine to me.

Pete.

Bil2
02-28-2006, 10:21 PM
Heck, man, do what we did as kids - put a playing card in the spokes...er..uh..prop. It'll sound just like the real thing. At least it did when I was seven. Ahhh, the Mickey Mantle rookie cards I wasted....Bil

Bigplumbs
02-28-2006, 10:32 PM
Another option might be to play this type of sound in you MP3 player and fly with your earphones in lol :D

Click me (http://angelfire.com/mi3/tomboshadows/Spitfire_Mk_14s_Fly_bys.mp3)

www.densplanes.co.uk (http://www.densplanes.co.uk)

watt_the?!
02-28-2006, 10:51 PM
absolutely awesome!!!..

is there any hope for us smaller scale modellers?...

Tim

Johnr
03-01-2006, 09:22 AM
Hi Tim,
Yes there is hope for smaller scale models. I am working on that now. A standard Micro is fed into a new Benedini 35w 30v mono amplifier. This amplifier is driven from the flight pack so a separate (sometimes heavy) power source is not required. It is planned to drive a single 90mm diameter 6 oz gramme speaker. So the overall weight increase should not be 1lb but more like half that. The sound output may be a couple of dB less, but I think it has more chance of catching on if the payload is a little lighter.

Will keep you posted as the components are now ordered from Thomas Benedini and I will test the first amplifier to see how it performs.

When someone finds a speaker of 100grammes or less then it should be even better. There has to be one, but we haven't found it yet.

All the best,

John

old git
03-01-2006, 02:19 PM
Hi John R,

I seem to remember from my distant interest in Hi Fi (I couldn't actually hear the difference) that speakers were loaded with concrete to allow the solenoid to work more effectively at driving the cone. Perhaps the frame of the speaker should be firmly attached to the heaviest components in the aircraft, battery maybe? This might enable more effort to be applied to the speaker cone with fewer mechanical losses.

Bundy
03-01-2006, 08:47 PM
Hi All

I haven't yet caught up with all the postings in here yet but I must say a HUGE congratulations to all those involved in putting the Corsair video together! That is really inspiring stuff and shows what this thread is all about. The plane, the sound, the video and the flying are all suburb and one can't help thinking we are witnessing the dawn of a whole new direction of RC flight. Those little 2 strokes and even the biggier 'gassers' just don't cut it in the realism stakes anymore.

I've been locked away in my shed building the last few weeks. I tend to waste way too much time on the computer when I start on it so when there is serious building to do I stay away from it. Changing to the 6" speaker has meant starting the 81" Corsair from scratch. All has gone well and should have it on its wheels with sound and motor next week.

Biggest problem has been the canopy. Cosairs usually took off and landed with their canopies open to allow quick access for rescue crews on carriers so I want mine to be operational. Like many things it is easy to do but hard to do well. I've spent nearly two weeks on this alone and still not really happy yet.

Hope to post some pics next week but again CONGRATS to all those involved in making that video so believable.

Richard

vax6335
03-01-2006, 08:56 PM
I sure wish I could put one of these in my H-9 Corsair, but I can't afford it.

CorsairJock,
Dang that's a neat picture of your plane! The Corsair is my all time favorite plane. It's nice to see so many on here.

Johnr
03-02-2006, 09:14 AM
Hi Richard,
Welcome back!
We thought you had been sunning yourself or 'out bush'. Look forward to seeing the pics of the Corsair. I know it is a bit off topic, but how have you managed to do your sliding canopy? I have one to do in the next few months and would like to see how others do it. I have milled a slot out of square hollow plastic which is about 5mm square with a 1.7mm slot but haven't progressed any further than that at the moment.

The new 35w mono Benedini amplifier might be of interest to you if you are weight watching. Thomas is also working on a 50v (max) version which should be good for your 10s Lipos and not require a voltage regulator.

All the best,

John

watt_the?!
03-02-2006, 09:22 AM
Hi Tim,
Yes there is hope for smaller scale models. I am working on that now. A standard Micro is fed into a new Benedini 35w 30v mono amplifier. This amplifier is driven from the flight pack so a separate (sometimes heavy) power source is not required. It is planned to drive a single 90mm diameter 6 oz gramme speaker. So the overall weight increase should not be 1lb but more like half that. The sound output may be a couple of dB less, but I think it has more chance of catching on if the payload is a little lighter.

Will keep you posted as the components are now ordered from Thomas Benedini and I will test the first amplifier to see how it performs.

When someone finds a speaker of 100grammes or less then it should be even better. There has to be one, but we haven't found it yet.

All the best,

John

:D this is so good!!...does it need to be 90mm?

Tim

Poof, Landed!
03-02-2006, 10:56 AM
I tried to post earlier (about the time this thread reached page 7), opps.
A few thoughts: Pete, Great Corsair and was thrilled to see your clip and hear the variable engine sounds. I, like EAMRC, have a background in audio mix down and recording, plus audio ET for music stores (Retired). The main thing I noticed was a low mid resonance around 750-800 Hz. It could be resonance assisted by the materials used for your speaker baffles but is also an easily amplified frequency by 4" speakers. To the guy who questions those poor 4" speakers, Bose uses eight 4" speakers for their professional stage speakers that can handle up to 350 Watts RMS (root mean squared= about 66% of the full peak to peak undistorted sign wave). IE: One cycle plus 50 volts @ "x" amps to minus 50 volts @ "x" amps would be 100 volts times "x" amps; the RMS would be approx 66v times "x" amps. Ofcourse that's divided by the number of speakers to find how much each 4" speaker (43.75watts @ 350W RMS:eek: input to Bose enclosure). HOWEVER: to get a good full range sound Bose created an active EQ that would increase the lower (below 180Hz especially) and higher (above 4KHz) as these don't come naturally to a small speaker.
Answer: A passive "notch filter" @ about 750- 800Hz center frequency, between the signal generator and the amp, or preamp and amp, which will drop the output to the speakers in this frequency range and allow more low and high end reproduction of your radial sound. Sorry can't give you the exact way to do this, just the right question to ask some one who can.
Gordon: on your external mike for your Video Cam, where you using a wind screen on the mic? If not, check it's manufacturer or a local musician for stores that might get you a quick fix. Used them a lot on stage out doors.

Yes I'm windy, sending my MoBo back for minor fix, maybe offline for a while. But MUST ask this question B4 I go:
Has anyone considered the affect of the wind stream across the speaker while in flight. The 3 best ways to ruin a speaker: a) too high input current burning up voice coil (umm, smells good:rolleyes: ), b) too high input voltage causing cone to over travel separates cone from voice coil (starts with distortion ends with silence:( , may or may not smell good), c) voice coil rubbing against magnet due to "improper flexing" of the cone (causes coil to lose it's center of travel within the magnet, shorts coil and smells good:rolleyes: ) may take out the amp too:mad: . Wind vs Cone Flex = POOF, eventually. JUST A THOUGHT or .... okay a few. Tom

modeldesigns
03-02-2006, 11:59 AM
Hi Tom,

Your contribution is just the sort of thing we need now to refine our existing attempts, thanks...i just wished i was qualified to endorse what you are proposing! Maybe others can.

It's early days yet for the speakers on the effects of 'wind stream' Tom but it must be one hell of a ride for them in all that turbulent blast!

My gut feeling is that a single, larger speaker may be the way to go for the lower frequencies, which is where we need to be to enhance the sound depth, in my opinion...

Hi Bundy,

I have seen the pics and video of your earlier Corsair and admire you 'starting again' to fit in a single, 6" speaker.

I have had thoughts on the subject too and have sketched a layout that i would like to try, and it could be applicable to other radial engined prototypes also.

My Corsair will be quite nose heavy when we eventually are able to run the amplifier off the flight pack (BEC style) so moving the speaker weight rearwards is not a disadvantage. It will also allow for a more appropriate volume of sound box. The rectangles either side of the speaker in the front view represent the flight cells.

A 'space frame' steel tube type structure holds the motor (in a simliar way to many full size) and is possible thanks to our very smooth operation.

Pete.

Johnr
03-02-2006, 02:04 PM
Hi Tim,
No not at all. It can be any size but it is a balance between size (and therefore weight) and sound output. Richard is going for a single 6" efficient speaker and if the model will take that then that is the best way to go. I started with a 50mm x 30mm 52 gramme speaker, it was not nearly loud enough. Then I doubled it and doubled it again and the single 4" speaker was better than all four! So you can see that if you are flying outside the lower decibel level from small speakers just dissappears when the model is a few metres away.

As a rough check you really need about 100dBa at 1m to be effective outside. We are lookng for lightweight high-output speakers and there are not many around. The Blaupunkt 90mm speaker can in theory handle high power input of up to 90watts (probably very distorted at this level).

My test rig on 'Heap of the Week' club trainer still uses these baby speakers to give the amplifier some limited load.

All the best,
John

Gordon
03-02-2006, 06:13 PM
Gordon: on your external mike for your Video Cam, where you using a wind screen on the mic? If not, check it's manufacturer or a local musician for stores that might get you a quick fix. Used them a lot on stage out doors.


Hi Tom

I did have the supplied foam plastic wind screens in place, see pic, but as the wind cancellation was inhibited, they didn't achieve much. Plus, the centre section of the mic is left open anyway, which is what I imagine caused the huge whistle towards the end as the wind blew past.

A friend told me that I need to buy a "dead cat" wind screen, which is a sorta fluffy sock to go over the mike. So I'll see if I can get one of those locally.

Gordon

Bigplumbs
03-02-2006, 10:15 PM
Hey John

After much pressure I have changed the connectors on my Larger Lipos and Planes

Dennis

watt_the?!
03-02-2006, 10:21 PM
hmmmm...i wonder if sound compression technology is going to rear it's head in this modelling area eventually.

not being a sound expert by any means, is decibel related to total sound output across all frequencies, as opposed to the sound coming from the loudest frequency?

i guess im wondering (out aloud) if a simulated engine noise can be made that uses less frequencies overall (gets rid of un-needed noise) and therefore can be effectively louder for less power.

(all this of course relies on whqat exactly db is )

Tim

Bundy
03-03-2006, 03:13 AM
Hi All

Interesting sketch Pete :) Attached is the pic of how I'm doing a very similar thing. I still haven't fired this up yet but dB tests have shown no drop at all with the motor like this. The motor mount is very similar to the one I've got in a 1/4 scale Tiger Moth so I'm not expecting any problems here.

On the question of dB readings - the meter I have has a weighting control being A or C. In A mode it measures in the 500Hz - 10,000Hz range which is what the human ear can hear. In C mode it measures across the whole spectrum. My tests to date have been in C mode - is this what you have using John? Not sure how much diverence it makes but will play with next time.

A 50 volt amp sounds just the ticket John. I'll get an email away to Thomas and see what else he can tell me. Do you have any other details - size and time frame??

Hope the pics show how I'm doing this sliding canopy John. Basically using brass section for the tracks as per http://www.rcuniverse.com/forum/m_964836/mpage_18/key_/tm.htm
This was the easy part - getting it to close tightly is not so easy. I've tried servos, levers, cables and snakes - all work to some extent but getting that tight closure is hard with the geometry of the Cosair's canopy and not stalling the servo or sail winch at the end. The system in the pic is simply, holds tight and will not drain the battery when holding close but it has its own problems.

Richard

modeldesigns
03-03-2006, 05:56 AM
Hi Richard,

The way to go! LOL.

Seeing the single, large speaker mounted like that it looks the business, at least for radial engined prototypes. Great stuff.

Can you tell me the volume of your sound box please?

...anyone for a Gloucester Gladiator?!

Complete with a sliding canopy, that's going to be a very sexy Corsair.

Thanks for your kind comments on the video too.

Pete.

Johnr
03-03-2006, 09:02 AM
Hi Richard,
Excellent photographs thanks very much. I will study them. If that doesn't work then nothing will. The Corsair is a natural for getting the speaker in the cowl, especially if you need weight up front. You build really quickly!

Thomas was testing his new 50v amplifier over the last few days and it blew up. I understand he has solved the problem now, but do not know when he will have one available. It won't be long I am sure. Knowing Thomas, the amplifier is likely to be very light.

The sound level in decibel range testing is in the A scale. As you say, that is the sound power level weighted to the frequencies that the ear hears, then that is the one to use. We do not want it weighted to the high or low frequency spectrum. It would be interesting of you ran your tests again Richard as you may even get a higher figure on the A range.

Hi Tim,
I do not think the unwanted frequencies can be removed from the engine noise as I suspect it is most of the frequencies all jumbled up. We could dispense with the higher frequencies but most of the speakers can handle these well. We are not agter hifi here, just a good middle / low range lightweight speaker.

Well done Dennis, I sure it will be worth it.

All the best,

John

ChinehamGeorge
03-03-2006, 10:10 AM
Hi Everyone

I have been watching this thread since Pete pointed it out to me, tempting me to "speaker up" my H9 Thunderbolt.

Just a thought here and for practical purposes I may be completely wrong, but in my experiences sound is quite directional.

Will a large speaker pointing forward like in Richard's (Bundy) Corsair be as effective on the ground when the model is flying as having speakers pointing sideways as in Pete's Corsair or downwards as in John's He111?

The question is..... should more thought go into the direction the speaker is pointing.

Pete, do you have any holes (like a speaker grille) cut in the side of your cowl to allow the sound to get out?

Cheers n beers
George

PS John, my club-mates are still talking about your HE111 since you visited us (Basingstoke MAC) back in Sept last year.

modeldesigns
03-03-2006, 11:27 AM
Hi George,

Good to see you in here!

Speaker location may prove to be an important factor, but it is an unknown yet. For scale models that will be dictated by the actual prototype anyway - some will have better locations possible than others.

I did not provided any additional holes in my cowling of the Corsair and the sound is certainly clearer and louder when the model is pointing towards you, so yes, quite directional in its present set up.

My first thoughts were that it must be optimum to have the speakers facing downwards but if you watch the video, there appears an equal amount of upper surface displaying as there is lower surface over the duration of the flight. Particularly when the model is the farest away (when the sound is less audible anyway) you see less of the lower surfaces so if the sound was emitting from there it would compound the problem even more? Food for thought anyway.

So yes, now you have an E converted 47 it is naked without sound now it is viable in H9 size models. I would like to see a single, larger speaker installation let into the firewall and bellowing out of the cowling front. You could then give John a run for his money at the Basingstoke E-fly this year!

Pete.

tahustvedt
03-03-2006, 06:33 PM
Is there a simple way to make a volume control? Like a potmeter between the TBS and amp for example?

I hope to maiden the Spitfire this weekend, without the sound system for now. I'll weigh it when I take it to the hanger to fly.

Bigplumbs
03-03-2006, 06:46 PM
And I was led to believe that all this electric stuff was supposed to be quiet......... lol............... Be careful Johnr you soon won't be able to fly on Sunday afternoons after the clocks change :) and Pete I dont think you will be able to put any more reviews in 'Quiet Flyer'............ :D ....... Weather looks good for Saturday !

Dennis

PS I should remember that no one likes a smart A**

modeldesigns
03-03-2006, 07:13 PM
Hi Tahustvedt,

Good luck on the Spitfire testing...it must give your LiPo cells a hard time in the temperatures you have to operate in.


Hi Dennis,

LOL, no problemo - i just don't have to turn switch 'SD' (sound) to on and no one will know the difference!

Pete.

eamrc
03-04-2006, 02:54 AM
Poof, Landed, is right on the money with my thoughts as well, low mid (500-1000hz) range chews up alot of power for something which is naturally resonated any way. Best thing to do is filter it and let nature do the trick on that and use your power for balls and details :D Yes on the winscreen issue we use something like the "Pole Cat" for ENG (Electronic News Gathering) works great !! Or you can skin a tribble and use that as well :D

http://www.enggadgets.com/core/media/media.nl?id=826&c=ACCT1441&h=7b912ffaeb3e357f722b

CorsairJock
03-04-2006, 01:52 PM
CorsairJock,
Dang that's a neat picture of your plane! The Corsair is my all time favorite plane. It's nice to see so many on here.

Thanks. There are a few more pics of mine and others here:

http://www.wattflyer.com/forums/showthread.php?t=2685

I REALLY need to add sound to it tho, LOVE the work that is being done here.

As for speaker direction: I'm thinking they should be pointed slightly rearward if possible, as the full scales are louder when one is behind them, and louder as they are going away from you. Maybe a single speaker at the bottom, canted slightly to the rear? And I agree: the bass needs to be there, these need to have the have the pants shaking rumble.

Poof, Landed!
03-05-2006, 08:43 AM
EAMRC: Great idea for the "pole cat", anything good enough for Professional Broadcasters is good enough for flight video too. Wish I could find my design books for passive and active filtering circuits, especially variable center frequency notch type filters or parametrics. Thanks, Tom

Johnr
03-06-2006, 04:52 PM
Hi Tahustvedt and all,
Try a 10k potentiometer between the Micro and the Amplifier. Are you wanting to use it for testing or for flying?

Good luck with the test flights. Have you fitted the speakers yet and if so where have you put them?

I think on the subject of speaker position we do not have much choice. If they can be fitted where they do not show, then that is a factor. It certainly works if they are fitted in the underside of the wing like the HE111, and they do not show up too badly. The radial cowl solutions look very good and seem to work very well. The centre of gravity issues also have to be dealt with and also it seems to be better with a larger speaker chamber. Lots of issues to wrestle with!

All the best,

John

tahustvedt
03-06-2006, 06:59 PM
I haven't started installing the sound system yet, I don't have speakers yet. I contacted Visaton.de about ordering from them directly. I think I'll put a 3S 1700 lipo in the nose to power the amp. This should hopefully compensate for the weight of the speakers which will be mounted right behind the CG.

The Spitfire has flown. The maiden happened this saturday, the day before the 70'th aanniversary for the spitfire. It flies very well and does not zip around like a racer. The speed is very scale looking. I managed to tip it over on its nose the first time I tried to taxi but didn't damage anything. :) With flaps down it can fly surprisingly slowly. The all up weight is 5965 g, which is less than the glow-powered weighs. I had to add 600 g of weight in the nose despite mounting both batteries and motor all the way forward.

Johnr
03-07-2006, 03:34 PM
Hi Thausvedt,
Congratulations on your successful test flight! As you know, Spitfires are prone to do that and 109s do the same. It is good that the flaps slow the model down well, what motor and battery combination did you use? Do you know what the wing loading of your Spitfire is?

I don't know whether you saw the Spitfire celebrations in the UK on Sunday where Alex Henshaw (at 93 years old) was in the back seat of the 2 seat Spitfire with four other Spitfires flying low around Southampton. He said he could probably still land it, but the insurers would not let him. With apparently 36000 test flights completed, it must still be like riding a bike. What a wonderful man.

John

tahustvedt
03-07-2006, 05:43 PM
I'm using an AXI 4130/20 on 8S Poly Quest 4000 mAh with an APCE 17x10 propeller. I should get~up to 20 minutes of gentle flying but I usually split it up into two short flights of ~7-8 minutes.

The wing loading is ~108 g/dm² (35,5 oz/sq.ft)

I didn't see the Spitfire celebrations. There's going to be an airshow here this summer so I hope we get to see a Spitfire, or at least some other warbird with a Merlin in the nose. :)

watt_the?!
03-07-2006, 10:43 PM
ok... i got me a peter rake eindekker (up to 60 inch) coming...what do i need to do with it? It'll be powered by a 600 class motor. Peter is going to draw it up specifically for the addition of a speaker setup.

other ones destined are SE5 and Tripehound.

Do you think i can get away with a geared speed 600?

Tim

Johnr
03-08-2006, 08:57 AM
Hello Tim,
You will have a job to get a decent flight performace with a 600 motor and sound. The all up weight that a 600 can usefully drag around is best kept to about 3lbs whether geared or not. The sound alone weighs 1lb although it is hoped to soon reduce it down to 1/2 lb. Suggest you consider an AXI outrunner or similar and Lipos to provide the increased power that you will need.

First estimate the all up weight and the wing loading, then we should be able to suggest a motor/ battery combination.

John

Bundy
03-08-2006, 07:59 PM
Hi All

I need some advice Guys. Following Gordon's excellent advice to keep the battery/ESC wires as short as possible, I've got my ESC and batteries inside the substantially sealed Corsair's fuselage/speaker box ( about 20 litres BTW Pete).

Trouble is I need to get some cooling airflow in there. I could simple put a hole through F1 and get plenty of air but this would in effect be a vent directly from the speaker's front to back. Second option is to vent air flow from the wing mounted oil coolers up into the fuselage and out through slightly undersized tailwheel/ arrestor doors.

I guess in the spirit of this thread I should allow for both and put the sound meter on it and quantify this sealed speaker box issue. Any thoughts??

Richard

old git
03-09-2006, 03:36 AM
Hi All

- - - - - -' sealed Corsair's fuselage/speaker box (about 20 litres BTW Pete).

Richard

Hi Bundy,

I've been reading and sometimes following this thread with interest and occasional comprehension. I am a bit perplexed by the volume of your speaker box, 20 litres!

Please explain.



old git AKA John L.

modeldesigns
03-09-2006, 09:37 AM
Hi Tim,

I agree with John re the Speed 600/model size, unless you mean a 600 size brushless motor?

Assuming you were to use existing available sound hardware then with a single 4" speaker, amplifier, sound module, enough battery to power the amplifier for one 10 minute flight and structure for a sound box i would estimate the payload to be 12ozs. WWI type models should have the advantage of being able to be flown more closely over a typical flight and hence the need for only a single speaker, but i cannot say for sure.


Hi Bundy,

Could you not partition the sound box where the ESC and cells are to allow an opening and outlet for the cooling air without disrupting the sound box function? What are you doing for charging, are you able to remove the cells to charge them?

Re the sound box volume, as John L asks, do you mean 2L or is it 20L? (the entire fuselage!)

Pete.

Bundy
03-09-2006, 10:29 AM
Hi All

Yep the entire fuselage is the speaker box. A bit hard to work out the exact volume because of all the wings, radio, batteries etc taking up space but the volume should be at least 20 litres. Theory is saying about 14 litres plus 20% should give ideal bass so using the whole fuselage should be about right altho it is not the ideal shape for a speaker box.

Partitioning the ESC and batteries is an interesting idea. However the need to remove the batteries for charging means it wouldn't really be possible in my current setup - next one tho! The batteries will be removable when the wing is off. Using 8000mAh lipos should give a good useable 2 X 10-12min flights between changes. One plug and two air lines will be all joining the wing and fuselage so I'm planning on battery changes not being a hassle - time will tell.

We're off to Noosa for 4 days so building will stop temporarily but a planked fuselage and sound test by next weekend is the plan.

Richard

modeldesigns
03-09-2006, 11:41 AM
Hi Bundy,

Apologies for doubting you! That should be a really interesting trial, looking forward to hearing that.

I took my Corsair to the BEFA (British Electric Flying Association) AGM last Sunday and ran the sound a few times. Alan Bedingham (our Technical Liason Officer) made a couple of suggestions - completely seal the gaps where the speaker frames mount against the sound box and secondly, where i have split the sound box in two with a former, remove the former to allow for a single sound box.

I have now done this and the sound does sound clearer and better defined, though it does highlight the problem of how we 'quantify' improvements made to the sound. You can see the white sealant applied around the speaker frames in the pic (i used bathroom sealant). Alan also pointed out the marked difference between running the sound with and without the cowling on - it is much better with the cowling on.

Pete.

Johnr
03-09-2006, 03:01 PM
Hi all,
Like the thought of using the entire fuselage as a speaker box Richard!

Fitting speakers in a large sheeted wing also allows one to get a lot of volume from the space between the ribs. However, my colleague who tested the original TSB4 Benedini unit for interference was concerned that if there is no air compressibility (i.e the the speaker is working in a very large box) at maximum power, then the cone driver can be blown out of the coil. Apparently the cone amplitude gets so great that the speaker cannot take it.

The other advantage of fitting a speaker in a sheeted wing is that you do not need all that extra weight of a speaker box. I know that in a Corsair you need weight up front so it is a natural place to put the speaker(s).

In the Hornet I have cut a large reinforced hole through the wing web so that it can utilise the large volume behind.

For measuring the sound improvements Pete you need a standard noise meter set to dBa. The overall sound pressure level will rise even if it is only the bass volume that increases. We are working with it at one metre distance. If I remember correctly every seven metres the sound halves, i.e. it goes down 3dB. One other thing we all ought to do the tests in 'free field conditions' where there are no reflections - outside! No problem for Aussies and now that the temperature is warming up then it shouldn't be a problem here.

John

modeldesigns
03-09-2006, 04:22 PM
Hi John,

Thanks for that. I understand what you are saying about a noise meter and the db levels (and the importance of measuring in an area with no reflections). What i was trying to ask was the difficulty in measuring improvements to the 'realism' of the sound, a more subjective topic than the actual db measurement alone? Maybe the two go hand in hand anyway.

Pete.

Johnr
03-10-2006, 12:10 PM
Hi all,
To measure the improved realism of the sound Pete I think you mean the increased loudness response to the bass. The db can be measured at all frequencies and I used to do it, but the measuring equipment was very expensive and I do not have access to it now.

The new 35w mono amplifier has just arrived from Thomas Benedini. It weighs in at only 24grammes without heatsink. I weighed the all up weight of a single speaker system (35w Amplifier, Micro and Blaupunkt odx92) and it came to 175grammes which is just a fraction over 6 ozs!

The question is - how loud is it, and I will have to see if I can set it up in the next few days.

Thomas says that the amplifier will take anything from 12v to 30v so those of us with 6s lipos should be OK. He said that his new 50v amplifier is still under development and it is not available yet.

Thomas has added an optional volume control pot between the Micro and the 35w amplifier and that will be useful to not annoy the neighbours!

John

modeldesigns
03-10-2006, 01:16 PM
Hi John,

I have no db meter or access to more sophisticated db measuring equipment...so i will have to rely on my own hearing. Not ideal, (both the hearing and the reliance upon it!) and it makes small improvements difficult to detect and quantify.

That is brilliant news on the new amplifier AND we can power it off the flight pack. Great news indeed for smaller models - 6ozs! Even employing two sets of amplifiers, sound modules and the two Blaupunkt speakers it is less weight to my present sound hardware (16ozs without power supply), and could be louder with it. Looking forward to your findings!

It's not only the neighbours John - running the sound at home is painfull to the operator too so it will be good to have the option of reducing the volume if required.

Pete.

watt_the?!
03-10-2006, 10:07 PM
i think i need to wait until these things get lighter for my apps. .5 lb i think is fine, less, of course would be better.

im happy to trade off db for realism for now also, and hopefully save some weight too.

Shall i just wait?

my plan would be to find the smallest airframe i can fit a 4inch speaker into, then overpower it with brushless/lipo.

looks like my brushed geared sp600 will spend another year in it's box...

Tim

tahustvedt
03-11-2006, 09:38 PM
Pete.
I saw a Hangar 9 Corsair today. A fellow modellers stores his planes in the neighbouring hangar and as I went in there today it was in his collection. It was a great looking model. I'm always pleasantly surprised when I see the Hangar 9 series. He has a H9 Texan as well. Both electric with AXI 4130/16 motors (on 6S I believe). I was there to fly my spit again but couldn't because a helicopter was testing on my runway. :)

I haven't started installing the sound system into the Spit yet. The norwegian distributor which Visaton directed me to hasn't answered my e-mails. I'm also waiting for a reply from Thomas regarding the new sounds. Do you guys have any PCM files for the TBS? It would be fun to have some other sound sets to play with.


Tor Arne.

modeldesigns
03-12-2006, 12:52 AM
Hi Tor Arne,

Amazing. An E converted H9 Corsair in your country and in a neighbouring hanger!

H9 models seldom disappoint and they have been great for me in 'cutting and trying' experiments in E converting and, more recently, getting sound into models. You have to turn an eye to the glossy finish, flat plate tail sections and only partly sheeted flying surfaces, but the fact is they work very well.

H9 have newly introduced an 81" razor back P-47 and it's a size of model i want to be at with an E powered warbird. It will easily carry the additional weight of the sound hardware, and allow for improvements too. That cowling will swallow some convincing speakers! (with thanks to an R/C Universe contributor for the pic).

I bought my Visaton speakers mail order from Radio Spares.

http://rswww.com/ (http://rswww.com/)

Pete.

tahustvedt
03-12-2006, 11:30 AM
Hmm.. rswww.com don't deliver to other countries than UK. there was a link to a norwegian distributor of RS but they only deliver to registered organizations. It's getting difficult to find a shop that wants to sell me speakers. :) Maybe I can order them through my work. I think they order from RS.

old git
03-12-2006, 06:46 PM
Hmm.. rswww.com don't deliver to other countries than UK. there was a link to a norwegian distributor of RS but they only deliver to registered organizations. It's getting difficult to find a shop that wants to sell me speakers. :) Maybe I can order them through my work. I think they order from RS.

I just looked in their website and found the following:-

RS suppliers in USA

Allied Electronics Inc.
7410 Pebble Drive
Fort Worth, Texas
TX 76118
United States of America

Tel: (1) 817 595 3500
Fax: (1) 817 595 6410

I don't know if that helps anyone. I am of the opinion that other areas are similarly supplied.

Keep up the good work lads, I am hoping for the time when I can purchase a ready made outfit to put in one of my infernal combustion powered jobs.

John L.

Johnr
03-13-2006, 11:12 AM
Hi all,
Testing all weekend and have some results.

The new Micro programme is much simpler than the development unit and both were set up in minutes. The toggle switch method for start stop and special sound is working, although one has to programme the start / stop first with one flick, and then the machine guns with three flicks. Not the most simple of systems for operating on the flying field, but it works.

The 2x40w amplifier now has a miniature volume control on the back of the circuit board. This is excellent and allows you to push the speaker output to the maximum.

Thomas had made the trial 30v 35w amplifier with a separate volume control and it is very necessary for the same reason.

It was connected to both the Visaton and then the Blaupunkt ODx 92. At 12v it worked well and also at 23v (6s Lipos) The volume was then adjusted (at the higher 23v voltage) and the single Visaton blew at just less than 2amps! The ODX was then tried and it has a theoretical maximum power capability of 90w which is three times the Visaton. Guess what - that one blew at just over 2 amps. Result - the Visaton is still the best and it is louder than the ODX. An expensive test.

The Visaton got up to about 98dBa just before it died. Sorry, it was inside again it was cold and wet outside!

The Beaufighter was then fitted up with the 2x40w amp in the fuselage with a new multifinned heat sink and two Visatons and ground tested for 13 minutes. All OK so over to our chief test pilot J Kinsey for a test flight at the increased all up weight. Once airborne the sound was switched on (an advantage of the toggle switch controls) and no problems. It sounds really good, especially on the ground.

I had the second flight and sound from the start. However, after a few minutes the sound volume decreased. It must have been that the amplifer overheated and was turning the output down with its autoprotection. The amplifier is now being mounted in the airstream in one of the cowls. So Tor, if you do not have a radial cowl you will need to get some air blowing over the amplifier and make sure it has plenty of thin aluminium fins.

Thomas reports that he will soon have some downloadable sound files for programming. I think he has done really well to cater for the requirements of the RC planes fraternity, and an 200g (8oz) or less system looks like it is possible, so long as the single Visaton speaker is taken to its maximum output via the volume control adjustment.

John

tahustvedt
03-13-2006, 01:14 PM
Ok. I think I will try to mount the amplifier inside a radiator cowling if there is room.

Maybe 8 Ohm speakers are more suitable with high voltages.

I might be able to get the speakers from Benedini now so that solves my problem. :)

modeldesigns
03-14-2006, 02:43 PM
Hi John,

Congrats on getting your Beaufighter into the air with sound, and it all reads successfull too. I agree, moving away from operating the sound functions off the rotary knob has to be applauded - i have never felt comfortable using them.

Did you manage to sort firing the motors up individually?

Pete.

ChinehamGeorge
03-14-2006, 03:30 PM
Hi John

I'm coming in late here on Pete's last comment.

If you haven't sorted it yet, you could always put the wires from the ESC's into 2 separate channels on the Rx and mix them together in the Tx with a switch on the Tx to activate the mixing. Just a thought!

I have done this on my TwinStar II (not quite as impressive as your HE111 :D )
I have also mixed the motors with the rudder so that when right rudder is applied the right slows down slightly.
I have it slow down as ESC's don't like being pushed at more the 100% which would happen if you made it speed up and rudder was applied when at full throttle.
It took some programming but was worth it in the end.

Cheers
George

PS the Basingstoke MAC Electric Fly-in is on the 10th of September this year, and would love to have you visit us again.

Johnr
03-14-2006, 04:01 PM
Hi Pete and George,
Unfortunately I ran out of channels on the receiver. I did programme a very complex mixing system from the Futaba website so that either or both motor(s) can be throttled independently from a three position switch, but that is as far as it got.

I am using all eight outputs on the receiver at the moment and as I like the toggle switch control for the Micro then I would need ten channels for separate controls! Hope to look at it again for the Hornet for next year.

Thanks for the invite to Basingstoke, early days yet, but weather and M25 permitting I hope to make it.

John

modeldesigns
03-14-2006, 06:28 PM
Hi Tahustvedt,

H9 models seldom disappoint and they have been great for me in 'cutting and trying' experiments in E converting and, more recently, getting sound into models. You have to turn an eye to the glossy finish, flat plate tail sections and only partly sheeted flying surfaces, but the fact is they work very well.


LOL. With appologies to Hanger 9, there latest offering has fully sheeted surfaces and aerofoil sectioned tail feathers - i can live with the glossy finish! It's 1/6th scale, 81" wingspan and will be a challenge to E convert...but plenty of room for sound hardware! Going to be good.

Pete.

ChinehamGeorge
03-14-2006, 07:13 PM
Hi Pete

I must also agree the gloss finish does take a little away from the overall effect.
How about a light coat of matt varnish/fuel proofer? it would be easier to do as it's in bits now :D and some weathering? :D

Cheers
George

Bigplumbs
03-14-2006, 09:26 PM
Pete

I cant believe you have got it already...... You are worse than me

Dennis

Johnr
03-15-2006, 09:57 AM
Hi Dennis,
That is just what I said, but it is a close run thing. It makes me feel old as I can remember the days when Pete used to design and make his own top quality models! (the clue is in the title).

Can you suggest anything that he should put on his modelling equipment to stop it rusting away? You lot are missing out on the head scratching, hassle, frustration, expense, but ultimate enjoyment of building. Just Richard, Gordon and me then?

John

modeldesigns
03-15-2006, 12:20 PM
Hi George,

I don't know of any matt finish that the film covering will accept but i have heard of the surfaces being rubbed down with wire wool to flatten back the gloss.


Hi Dennis,

LOL. The new 81" P-47 just HAS to be E converted...and with sound of course!


Hi John,

Don't make me feel any more guilty than i already am!


....with apologies to Bundy for taking things off topic.

Johnr
03-23-2006, 02:45 PM
Hi all,
The Beaufighter flew again yesterday with the amplifier mounted in the cowl of the starboard engine with cooling fins extending behind the dummy cylinders. There has been lots of additional wiring, but the cowl air inrush certainly keeps the amplifier cool. There were no interference problems.

The 109 also flew with sound for the first time. Luverly. The 30v amplifier was mounted in the starboard radiator and powered directly from the 6s lipos. Therefore no additional battery for the sound is carried. A single Visaton R10s has been mounted in the chin oil cooler section and tweaked to give the maximum output that I think it can take. The results are very good for one speaker, and once again there were no interference problems.

The 30v amplifier is not as efficient as the 2x40w amplifier and it does need more cooling. Without a cooling fan (or prop blast), the heat sink can get to over 110 degrees C, but the wing radiator worked, and it was barely warm after the 8 minute flight. However, the ambient temp was 5 degrees from a north-easterly wind all the way from Tor in Norway!

The weight gain is only about 8 ozs, so this really makes it suitable for smaller models. The all up weight of the 109 is now 9lb 5ozs.

Now all I have to do is creep up sun behind Pete's Corsair, arm the guns and .......

How is your Corsair Richard? Have you got that sound installed yet Tor?

John

tahustvedt
03-23-2006, 03:09 PM
The speakers should be here tomorrow or at least by monday. On tuesday I got a letter from customs saying the package had arrived.

modeldesigns
03-23-2006, 06:23 PM
Hi John,

Well done on both airframes. Can you get a video of the 109 starting up? (and even better - some of it flying). If it's the same recording you played me at Raydon then the world needs to hear it!

Pete.