Plasma Tweeter Videos

March 27, 2008 by Lukas Gilkey



A couple diy plasma speaker videos popped up on Youtube recently. I've been fascinated with plasma tweeters for a while now and even got to see some in person at the Rocky Mountain Audio Fest last year. Definitely opens your eyes as to what can be used to reproduce sound.

Videos after the jump.

The comments from the author are below both videos.




"Now built the completed circuit on a single PCB. Made vertical electrode setup from tungsten carbide (bottom) + stainless steel (top). Reflector made from PVC pipe with rear mirror, which can be backlit with RGB LED's. 1/2" gap at base to aid upward convection / cooling and improve flame stability. EHT now slightly lower and the gap size has been reduced. Track is 'Hold Me Now' from the Thompson Twins - chosen purely for it's good dynamic range, vocals & clever percussion ! Let me know if would like to see & hear any particular song - see what I can do ;)"






"This is a prototype of a FM modulated plasma arc speaker / tweeter. Have since built this circuit on a custom PCB & made an improved vertical discharge setup, using tungsten-tipped electrodes (see my other videos). This stops the plasma hopping about and causing unwanted distortion...
Technical stuff : Supply voltage for output stage in this design is 50V DC - driver is a single IRF740 HEXFET power Mosfet. Flyback driver uses a SMPS IC from a computer power supply. External oscillator & High-pass filter for the audio, is a uPC4570. EHT output is roughly 60KV. Make sure you subscribe, to get regular updates on this project & others :)"

Source: Gizmodo
Comments (6)
Doodaddy 3 months and 3 weeks ago

Am I retarded for just not understand what in the crap is happening there?!
lukas 3 months and 3 weeks ago

Pros: VERY low moving mass, extremely responsive, looks badass
Cons: Creates poison gas, limited frequency range and output

Wikipedia has a pretty good entry that explains it well.

Plasma/Ion tweeter

Because ionized gas is electrically charged and so can be manipulated by a variable electrical field, it's possible to use a small sphere of plasma as a tweeter. Such tweeters are called a "plasma" tweeter or "ion" tweeter. They are more complex than other tweeters (plasma generation is not required in other types), but offer the advantage that the moving 'diaphragm' is optimally low mass, and so very responsive to the signal input. These types of tweeters are not capable of high output, nor of other than very high frequency repro, and so are usually used at the throat of a horn structure to manage usable output levels. One disadvantage is that the plasma arc typically produces ozone, a poison gas, in small quantities as a by-product. Because of this, 1980's German made Magnat "magnasphere" speakers were banned from import to the USA.

LINK
Doodaddy 3 months and 3 weeks ago

It's almost as if we live in the 21st century or something.
lukas 3 months and 3 weeks ago

Woah there, don't get ahead of yourself. That would mean that people should be flying around in "winged machines" and communicating with other people via an electronic box. ;)
veedubb8 3 months and 3 weeks ago

Wow, this is stunning. It's mesmerizing to watch and it seems to sound pretty good to boot! And, eh, what's a little poisonous gas? What doesn't kill you can only make you stronger, right?
SPLChris 3 months and 3 weeks ago

I wish I could do that.
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