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Speakers? In Planes?

#1
So I had a wild idea, thinking it wouldn't be worth the weight added to a plane- but then I did it, and kept track of added weight.

I put a Bluetooth speaker in my Origin 300i. Bruh.

I swapped out the drivers for 8 ohm 3W coin exciters and attached them to the wings. Sound is surprisingly high quality, added weight is ~2 ounces, including a dedicated 1S battery, and the system charges off the BEC.
Here's a demonstration using a parody of "Gaston" done by the Newfangled Four:

Now, there's an alternative, more powerful setup I made a parts list for that would be easier to assemble, 4-5 ounces (I think), and would have over 30W of speaker power, and run directly off a 3-6S flight battery:
4 of these, 10W coin exciters (same brand as the 3W ones I used):
https://www.parts-express.com/dayton-audio-daex25ct-4-coin-type-25mm-exciter-10w-4-ohm--295-220
And one of these, a 24V Bluetooth speaker amp (remove the screw terminal block for weight reasons):
https://www.amazon.com/dp/B07S79BDH4/?tag=lstir-20

I'd assume trying to operate the speaker and fly at the same time would be a bad idea due to RF interference, but it's still a nice thing to have at the field.
 
#2
Hmm, does anyone know if it would be possible to use a powered coil in an exciter rather than a permanent magnet? Could reduce the weight. I just looked up the weight of the 30W system- looks like it adds a whole pound.
 
#3
Updated idea: An ESC that runs engine sound through the motor coils. Start with a 32-bit processor that has 3 or 4 integrated DAC outputs, and run each coil off of one DAC- and here's the important part- using a 0-3.3V triangle wave source to offset the analog output, run it through a saturator MOSFET array, then a 3 by 2 output gate driver IC, then through the power MOSFETs, then we start talking about connecting it to the motor and by God will this be a lot easier if a sensored motor is used.
 

FDS

Well-known member
#4
I would use a vibration/resonance speaker. I have seen them used on model railway back boards for sound, they use the board as a resonator, making a bigger sound from a smaller lighter speaker.
However the way we usually get realistic engine sounds is to use a realistic model engine. Check out some of the large scale warbirds, some of those sound really great. EDF jets can also be surprisingly jet like in sound.
 
#5
I would use a vibration/resonance speaker. I have seen them used on model railway back boards for sound, they use the board as a resonator, making a bigger sound from a smaller lighter speaker.
However the way we usually get realistic engine sounds is to use a realistic model engine. Check out some of the large scale warbirds, some of those sound really great. EDF jets can also be surprisingly jet like in sound.
I think the term is “exciter.” 12 blade EDFs don’t need this, rather this is for smaller scale warbirds, where a realistic sounding engine just isn’t feasible.
 

FDS

Well-known member
#10
I don’t care what my planes sound like enough to add any weight or cost to them. Plus the number of times they end up scattered over the field I don’t think the gear would survive anyway.
 
#11
This is for scale pilots who care about cosmetic detail and want a more realistic sound. Typically their planes are in the 800mm-1700mm wingspan range, where realistic scale engines aren't an option.