Plasma Headphone?

[Czilla9000]

Has anyone actually thought of designing and building an iconic plasma headphone? Could be interesting. It has no moving parts.

 

[Onix]

They were selling one on eBay sometime ago and there was talk here about them. Check this thread.

http://www5.head-fi.org/forums/showt...ghlight=plasma

 

[Prune]

The PlasmaSonic headphones had a lot of problems. You can find out details at Audioasylum:
http://db.audioasylum.com/cgi/m.mpl?...neral&n=335595
Frequency response:
http://db.audioasylum.com/cgi/m.mpl?...hones&session=
Corona discharge is the wrong approach. A glow discharge is what we want. As far as I know, only Hill's Plasmatronic speakers used the latter method. See here for more info on them, and also US patent 4,219,705:
http://members.cox.net/jayphil/plasma.html
I'm working on doing this with air instead of helium. There's no reason this method can't be used in headphones, though UV blocking may be needed this close to the skin.
But why bother, when top-end electrostatics (Omega II) will get you 99% there, without the ozone and oxides of nitrogen?

 

[Onix]

What I would like to know it's how different are the headphones, from, lets say, the plasma tweeters. I know the tweeters need a flame, and an extremely hot one. How would the headphones work then, do they have a "flame" of sorts?

 

[Czilla9000]

Yah.....electrostats are basically massless anyway.

 

[Prune]

Quote:

Originally Posted by Onix What I would like to know it's how different are the headphones, from, lets say, the plasma tweeters. I know the tweeters need a flame, and an extremely hot one. How would the headphones work then, do they have a "flame" of sorts?

There are two types of tweeters, one type is Hill's (DC glow discharge), and then the rest, including all the DIY designs out on the web (RF modulated corona discharge, usually tesla coil driven). The "flame" in Hill's is not a flame as nothing is burning, but a glow discharge helium plasma, with the temperature coming from electricity.
The other type are problematic because they generate more ozone and oxides of nitrogen, and TONS of interference. They also have worse low end frequency response and almost always use horn loading.
The headphones use a corona discharge, but are surrounded by electrode grids, which unfortunately collect dust and gunk just like those ionic air cleaners, and are a main cause of the problems with these headphones. Mini-hill type configurations would work much better in a headphone arrangement, again as full-range drivers.
Yet another variation is Nelson Pass' experimental "ionic cloud" speaker, which used a corona wire grid sandwitched between grid electrodes; the corona wire created a sheet of ionized air that acted like the membrane in an electrostatic panel. This generated so much ozone and oxides of nitrogen that it sent Pass to the emergency room. Don't try this at home

 

[Onix]

Quote:

Originally Posted by Prune There are two types of tweeters, one type is Hill's (DC glow discharge), and then the rest, including all the DIY designs out on the web (RF modulated corona discharge, usually tesla coil driven). The "flame" in Hill's is not a flame as nothing is burning, but a glow discharge helium plasma, with the temperature coming from electricity. The other type are problematic because they generate more ozone and oxides of nitrogen, and TONS of interference. They also have worse low end frequency response and almost always use horn loading. The headphones use a corona discharge, but are surrounded by electrode grids, which unfortunately collect dust and gunk just like those ionic air cleaners, and are a main cause of the problems with these headphones. Mini-hill type configurations would work much better in a headphone arrangement, again as full-range drivers. Yet another variation is Nelson Pass' experimental "ionic cloud" speaker, which used a corona wire grid sandwitched between grid electrodes; the corona wire created a sheet of ionized air that acted like the membrane in an electrostatic panel. This generated so much ozone and oxides of nitrogen that it sent Pass to the emergency room. Don't try this at home

Thanks for the info. Now, that's something I have to read twice before actually understanding a thing

 

[Czilla9000]

Plasma Glow Discharge panel instructions: http://jnaudin.free.fr/html/s_gdp1.htm

Requires 10 kV @ 4kHz AC.

If I am correct, that is NOT a good FR. Whats the point of this method if the response is so bad?

 

[bangraman]

Everything I've done seriously for amusement has always ended up as a risk to life and limb. I think I've found my next headphone

 

[Edwood]

Quote:

Originally Posted by bangraman Everything I've done seriously for amusement has always ended up as a risk to life and limb. I think I've found my next headphone

LOL, who will be the Head-fi "Super Dave"?

-Ed

 

[Prune]

Quote:

Originally Posted by Czilla9000 If I am correct, that is NOT a good FR. Whats the point of this method if the response is so bad?

This is not intended to be a hi-fi driver, but to demonstrate a physical effect. In any case, if you'd bothered to check the main page of that site, you'd have seen that the webmaster is actually a crackpot. The place is full with 'free energy' and overunity scams.

The proper resources include links such as:
http://www.plasmatweeter.de/
http://www.angelfire.com/electronic/...s/tweeter.html
http://www.geocities.com/ResearchTri...866/plasma.htm
and so on (the above are all tesla coil driven corona discharges)

The better method, glow discharge (Hill's speakers) is not discussed in much detail anywhere, with the best page being http://members.cox.net/jayphil/plasma.html
The following graphs from that page show the performance of modified Hill helium plasma tweeters:

Response curves:

Magnitude is +/-1.5 dB... No discontinuities or weirdness in either magnitude or phase. Now the trick is finding a good match for the low-end drivers

Waterfall:

Step response of above measurement:

 

[Czilla9000]

Interesting.

Anyway, do you think a Hill type headphone would be more accurate than a well-designed electrostatic headphone (Omega Series)? By how much?

BTW, since the coast is clear....is it safe to say that all things considered electrostats are better (more accurate) than dynamic phones? Since most of the headphone boys don't visit this forum, I think I can ask this question here and keep the peace.

 

[drewd]

Quote:

Originally Posted by Czilla9000 BTW, since the coast is clear....is it safe to say that all things considered electrostats are better (more accurate) than dynamic phones? Since most of the headphone boys don't visit this forum, I think I can ask this question here and keep the peace.

You take your life into your hands

I've listened to Stax Lambdas and loved them. Like anything, though, I suspect that it's a matter of opinion. I have electrostatic loudspeakers (Acoustat 1+1) and I love 'em to death, even though their bass response is anything but authoritative. The level of detail and realism from them is really awe inspiring - and that's from a nearly 20 year old speaker! I get the same feeling from electrostatic headphones. And they're a lot more convenient than 8-foot tall speakers!

-Drew

 

[Prune]

Quote:

Originally Posted by Czilla9000 do you think a Hill type headphone would be more accurate than a well-designed electrostatic headphone?

Only if it's well designed

In other words, it might be hard to achieve with DIY methods, although theory says its potential is better.

Quote:

By how much?

You can't quantify this, as it remains a subjective measure. THD and IMD do not necessarily correlate with perception due to the ear being particular to specific distortion profiles rather than these overall summary measures. There is a new metric proposed that is weighted specifically to correlate with perception, but the jury is still out (http://www.gedlee.com/distortion_perception.htm).

Quote:

is it safe to say that all things considered electrostats are better (more accurate) than dynamic phones?

Yes, unless you believe Nelson Pass' idea that air is single ended

Dynamic drivers have far more distortion than the source and amplifier, whereas electrostatics can achieve much improved numbers. Take a look at these DIY full range 8' tall ESL: http://www.ele.tut.fi/~artoko/audio/...range_esl.html.

Quote:

Since most of the headphone boys don't visit this forum, I think I can ask this question here and keep the peace.

You sure?

 

[customcoco]

any updates since 2004?