Sound may be recreated by playing back pulses of constant amplitude, properly placed. See link for a coding method deviced by Roman Black. It may also be recalled that some very high quality converters for digital audio use a single bit stream.

So a speaker can be devised by creating explosions at a high enough frequency, and filtering, or muffling, the resulting stream of explosions.

The NEELCO(tm) explosive speaker consists of a combustion chamber followed by a large horn and some sound filtering inside it to shape the frequency response. Vaporised gasoline and air mixture from a carburettor is fed to the chamber and ignited by a spark plug, which is controlled by the bit stream derived from music according to the algorithm devised by Mr. Roman Black.
-- neelandan, Oct 05 2006

Sound encoder software home page by Roman Black http://www.romanblack.com/picsound.htm
Shows how to encode high fidelity music in a single bit stream [neelandan, Oct 05 2006]

Yamaha have an integrated circuit driving a speaker with pulses http://www.global.y.../2004/20040831.html
So eliminate the middle man, and produce the pulses by more efficient means! [neelandan, Oct 06 2006]

Halfbakery: The Expode O Phone The_20Explode_20O_20Phone
Similar? [jutta, Oct 06 2006]

Booooooom!-When loudpeakers catch fire http://musicthing.b...ers-catch-fire.html
[Dub, Oct 09 2006]

(O.T) Mutually assured destruction http://musicthing.b...inch-subwoofer.html
60" Subwoofer [Dub, Oct 09 2006]

Related technology http://www.swtpc.co...e_Amplification.htm
Flame Speaker from 1968 [csea, Oct 09 2006]

Rubens Tube http://musicthing.b...nt-involves_11.html
[Dub, Oct 12 2006]

[jutta] Similiar in the manner of exiting the sound resonator.

But in the linked idea the explosions set an acoustic resonator into oscillation on a single note (plus harmonics). This idea utilises the filtering effect of an acoustic transmission line to attenuate the higher harmonics and so provide sound approximating to the digital representation.
-- neelandan, Oct 09 2006


[csea]Brilliant link!
-- Dub, Oct 09 2006


Can a gasoline flame be ignited and quenched in 20 microseconds? This would be necessary for high fidelity reproduction. (1/44kHz~= 20usec.)

Might require catalytic conversion of exhaust products and an exhaust tube.

See [link] for analog flame loudspeaker from the 1960s.
-- csea, Oct 09 2006


[Dub] Thank you! I built one of these using a bunsen burner and a 6V power transformer. It worked, but the noise of the burner was almost at the level of the audio.

I do recall seeing commercial flame loudspeakers at an Audio Engineering Society convention in the early '70s.
-- csea, Oct 09 2006


The guys all look so, well..., hip.
-- Dub, Oct 09 2006


If you are willing to give up the constant amplitude part, you might be able to modify an ink jet print head to pump out a flammable liquid into an air stream with a glow plug. Or for ramp up, a fuel injector from a car.
-- cjacks, Oct 09 2006


Hot off the press
-- Dub, Oct 10 2006


Great links, [Dub], though I couldn't check out the videos. I'm on a slow dialup. And I should try the flame amplification linked to by [csea].
-- neelandan, Oct 10 2006


linky
-- Dub, Oct 12 2006



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