Plasma speakers anyone with info?

Acapella audio of germany is currently producing three models with horn loaded plasma tweeters (and they've apparently figured out away around the ozone problem). This is your best bet. It may be something like acapella??.de Nelson Pass (of Pass Labs) built one back in the '70's called the Ion Cloud so he may be a source of information. I have seen one or two other units that looked to be current production models: one a japanese company and the other using TAD drivers.

I own a pair of the before mentioned A-Capella Ion speakers and I'm still very much alive.
They have the ozone problem licked a hundred percent and there are no precautions to be taken. I see no drawbacks except the price, which is hideous! (About $ 3500 to 4000 a pair, if you can get them at all, because A-Capella does not sell them singly, but only together with their speakers.) The advantages are a far better sound stage rendering, much more depth and you can listen far deeper into the soundstage. They take careful placing and blending, but which speaker doesn't and to these ears they beat every tweeter I have ever listend to. (Decca & Sequerra ribbons especially, which I know best). You can adjust the frequency, where they set in. Besides they go up so high, that with certain music you have amorous bats clamouring to get inside! (-; You'll get more information through www.acapella.de
Cheers and a merry X-mas to you all!
Detlof

There's a big difference between the Hill Plasma type of
speaker and the "Ionovac/Ionophone" horn loaded style of
"plasma" speaker.

The former used a large gas plasma that was directly
modulated by AF at high voltage.

The latter uses an RF signal to generate a very tiny (and
hot) plasma which is indirectly modulated by AF high
at high voltage.

Both are similar in terms of needing a plasma, but the
latter case must deal with the effects of horn loading,
and limited LF response.

Both have some background hiss from the plasma itself.

The Hill had the single most impressive mids and highs
that I can recall - fantastically coherent and dimensional.
Their bass was less wonderful. The Hill used "Argon"
welding gas to create the plasma, so it "leaked" into
the room (presumably on the floor, as it is heavier than
air), so they are safe with an exhaust route for the remaining
gas to get out of the room.

Neither make excessive amounts of Ozone. There's more ozone in the air in any major city than these are likely to produce in your listening room.

Magnat made a pure plasma tweeter many years ago, it was an
omni from what I understand - never heard one.

I did an on paper design of a wide range omni, direct radiator
plasma driver some years back...I think it would work.

I don't know about the Acappela tweets, anyone got a URL?
Are they horn loaded??

_-_-bear

Bear, they are hornloaded, don't hiss and the URL is
www.acapella.de

Thanks Bear. The Magnat's were the ones that i was thinking of but couldn't remember the name. I'm still looking for the address, but the guy had several pairs of various models, some still sealed in the box.

I remember seeing some stuff about the Hill woofer. It supposedly had the fastest transient response / most linear output at 30 Hz of any woofer available at the time of production. Even with that good of a woofer, the mass of a 14" dynamic driver will always sound slow and out of synce when mated with what we would consider a "massless" radiator.

I have a friend with a TON of the Dukane Ionovac's. Some have never been fired and are still in the original packaging. Would it be worth hitting him up for some of these ????? Sean
>