sjb@dalek.UUCP (Seth J. Bradley) (10/17/90)
In article <1990Oct16.145517.10214@ariel.unm.edu> ee5391aa@hydra.unm.edu (Duke McMullan n5gax) writes: >In article <2142@oucsace.cs.OHIOU.EDU> bwhite@oucsace.cs.OHIOU.EDU >(Bill White) writes: >> I seem to recall reading or hearing about a beast called a "plasma >>speaker" - which used some form of a gas plasma (I think argon) to produce >>high-quality sound. I guess it even went to market, but was too high >>priced and too bulky (you had to have a tank of argon to make it work) >>for most people. Is this just another urban myth? >Back in the sixties, there was a plasma tweeter on the market (Ioneer, or >something like that, I think.) for a while. It died, apparently. I heard >stories of ozone-induced nausea, bad shocks and even a fire. (Note that I >_do_not_ speak for the veracity of any of those stories: they're _rumors_!) >Whatever the reason, it went away. This sounds a lot like the Ionovac. There apparantly were a fair number made, and there are people who still collect them and manage to get them to work. I've never seen one, and don't know how exaggerated the danger reports were. >In the early seventies, Alan Hill of Albuquerque developed a virtually >distortionless corona/plasma speaker and marketed it in the late seventies. >It was an "upscale" (read: expensive as hell) device, and as far as I'm >aware was a commercial failure. I don't know if he ever sold any of the >things or not. He must have sold a significant number, because I occaisonally see them used (for as little as $2500/pr.). I was always under the impression they used helium. While production has been intermittent, as recently as last year they were listed as available for $12,500/pr. in the Audio Directory. They weigh 580 lbs./pr., and the plasma driver only operates at 700 Hz on up. Conventional cone drivers (a 14" and 6 1/2") handle the rest of the audio range. A French company is trying to market a full range ion speaker. There are a few problems though. Maximum SPL is less than 90 dB, they may have some ozone leakage, and they are priced at over $100,000/pr.! They also weigh about as much as the hill, and are 4 ft. wide. Followups to rec.audio. -- Seth J. Bradley Path: {uunet}!iwarp.intel.com!dalek!sjb