So you're an
audiophile and you've seen every speaker technology that's out there. You've tried giant German horn speakers, "W" sandwich composite cones, titanium alloy woofers, magnesium/foam drivers, you've tried them all. But of course you need more, you want
extreeeeeeme listening. Your $20,000/pair tube
monoblocks should be driving the best. Well, you, my friend, need a
plasma tweeter.
The plasma tweeter is a radical design for
high frequency sound reproduction. Instead of a moving cone or
diaphragm to create sound in the air, a ball of plasma is used, much like those
Sharper Image plasma globes. The circuitry uses a high-power transmitter
oscillator which drives a
tesla coil to produce a small plasma flame. The
current producing the flame is modulated by an audio signal. Bigger signal, bigger flame. The changes in flame size cause pressure waves in the air (
a.k.a. sound).
They are supposed to sound amazingly good. Frequency range is ~3kHz up to ~40kHz at up to ~108dB and the sound radiates sphereically from the flame source. Because the flame can change its size much more rapidly than a dome can move in a traditional tweeter design, muscial
transients are rendered particularly well. One drawback is that the tweeters produce
ozone, so don't play them for 10 hours in an unventilated room.
Additionally, because the upper frequency range extends to 40KHz, there is no need for a SuperTweeter for ultrasonic frequencies. Because of this, the Plasma Tweeter may be a good match for high sample-rate recordings such as
DVD Audio and
SACD which contain ultrasonic information.
At the moment it is extremely hard to find manufacturers selling these units. It is mostly a
hobbyist market and there are several places online to find schematics and information on how to build them yourself. However, a large portion of it is in German.
Pictures available at http://www.plasmatweeter.de