Audio Modulated Tesla Coils

[QwertyAccess]

I'm curious if anyone has gotten a chance to experience Audio Modulated Tesla Coils in real life? Or if anyone got any random comments about them, they seem pretty interesting to me :P. Yes do i realize they sound very electrical, but seems pretty neat nonetheless. I saw a comment somewhere that it sounds like sound coming out of nowhere. I wonder what kind of frequency range these things got. (vibrate the air?). Anyone got any impressions of them?

Giant tesla coil playing game music, mario, tetris ^^
http://www.hauntedfrog.com/gt/movies/2007/duckon/SingingTeslaShow.html (http://www.youtube.com/watch?v=lI6q18QNZns)

small one, playing some music, but seems to have quite some range
http://www.youtube.com/watch?v=6tKo_3DzdSU

[toddalin]

I'm not so sure that you are "hearing" sound produced by the modulated tesla coil as opposed to the the tesla coil just "dancing" along with the music such as you would see with a color organ. (Especially the Indian music.)

[QwertyAccess]

well theres tons of audio modulated Tesla coils on the internet, so i can imagine that its actually really producing the sounds itself when its tuned to do so. You tube has a good amount of it, people amplify some of their instruments with it, and i personally think it sounds neat.

So i highly doubt its merely following the music.

http://youtube.com/watch?v=7xnLqSGtkOk
http://youtube.com/watch?v=BiUlqecQKUo#

[Allanvh5150]

The arc sure does sing!
The corona discharge from the solid state tesla coil can be made to produce sound by modulating the amount of power delivered to the arc. This is similar to the way in which an AM radio transmitter works, in that it manipulates the envelope of the Radio Wave in order to impress sound onto it. The difference here is that it does not require a radio to hear the sound !
As the power delivered to the arc is varied, the temperature of the ionised air varies. If the power increases the arc becomes hotter and expands. Conversely if the power is decreased the air becomes cooler and contracts. This expansion and contraction produces the sound waves that our ears detect.
I think I should build one, Allan.:)

[Ken Andrew]

Have you thought of this similar concept. In the early 80s there was a Magnat (German?) speaker box which had a tweeter which looked like a tesla coil. It was enclosed in helium gas cloud to prevent arcing. The treble response was superb. Not very WAF because of the gas pipe to a Helium tank/bottle had to be replaced every 3 months.