DIY Plasma Tweeter Anyone?

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Clashing

Member
2014-02-05 6:39 pm
Hello,
Lately I have become interested in plasma tweeters. In the commercial realm, Lansche and Acapella seem to be the only two with the technology to produce them (patent related? Idk...). Anyway, I did see this on the DIY side of things...
Ulrich Haumann's DIY PLASMA TWEETER
Plasma Driver DIY
http://m.youtube.com/watch?v=qmqp80euV1U
http://m.youtube.com/watch?v=qmqp80euV1U
Make a Plasma Arc Music Speaker ? Electronic Music | Make:
Plenty of people seem to have an interest, but very few people seem to have actually built them. Are they really that complicated? And are they even really all that?

Anyway, on the technical side, I understand that the idea of a weightless diaphragm is a theoretical ideal, but is that really practical? Wouldn't you need some mass, however slight, to accurately reproduce the sound of an object with mass vibrating?

Btw, anyone with measurements of these drivers, DIY or commercial?
 

andy19191

Member
2005-04-17 11:42 am
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Anyway, on the technical side, I understand that the idea of a weightless diaphragm is a theoretical ideal, but is that really practical? Wouldn't you need some mass, however slight, to accurately reproduce the sound of an object with mass vibrating?

There are two mechanisms involved for moving the air: expansion by heating (monopole) and the particles whizzing between the electrodes bumping into air particles and exchanging momentum (dipole). So there isn't much mass involved by what is doing the pushing around but the air that is being pushed needs significant inertia (mass) or else it would move out the way without compressing to create sound. There would be no practical difference between a light or very light diaphragm once most of the mass being moved is that of the air to be compressed.

Btw, anyone with measurements of these drivers, DIY or commercial?
If you read French there are some details here and one or two papers in English with measurements somewhere.
 
Here is a commercial one - they are reputed to be the best sounding speaker.

Hill Plasmatronics Type 1 loudspeaker | Stereophile.com

hillplasmatronics.com

Hill-Plasmatronics-1A-Pair.jpg
 
Anyway, on the technical side, I understand that the idea of a weightless diaphragm is a theoretical ideal, but is that really practical? Wouldn't you need some mass, however slight, to accurately reproduce the sound of an object with mass vibrating?

The hot plasma moves the air and it's not without mass, it's essentially heated air which expands and contracts and moves the 'normal' air around it.

The plasma-tweeters are amazing but bring a lot of problems with it. The effiency is very low and the possible amplitude is quite small too, which means, they work only on mostly very high frequencies and you need an active setup. The electronics work with very high frequencies, which can cause radio interference. The ozone could theoretically be eleminated by a catalyser (is that the correct word?), for DIY that's quite an issue, if you skip that, you have to live with headaches.
 

Clashing

Member
2014-02-05 6:39 pm
Here is a commercial one - they are reputed to be the best sounding speaker.

Hill Plasmatronics Type 1 loudspeaker | Stereophile.com

hillplasmatronics.com

Hill-Plasmatronics-1A-Pair.jpg

Interesting, that model seems to use helium instead of ozone, which would eliminate the ozone poisoning that Morton mentioned. Aside from the issue of going to the hospital for poisoning, what did Mr. Pass think of them?

BTW, Im less familiar with the circuitry involved in one of these tweeters... So forgive me but what is a catalyzer and is it DIY possible, assuming cost no object?
 
BTW, Im less familiar with the circuitry involved in one of these tweeters... So forgive me but what is a catalyzer and is it DIY possible, assuming cost no object?

A catalyzer/catalytic converter is the same or simmilar thing you have in your car exhaust. The mesh of the cage have to be very tight. It works different than a filter, it's not consumed or polluted by it. The presence of specific materials changes the way a reaction happens or changes the molecules passing it. To build one, you have to bring the catalyst material onto the cage, it has to have a specific surface to work. With 'normal' DIY methods and tools you can't achieve that unfortunately.

-> https://en.wikipedia.org/wiki/Catalysis
 
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