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Det har ju inte hänt nåt på 85 år? Eller?

conan

By conan
in Euphonia Hififorum

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conan

conan

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När Chester Rice & Edward Kellogg uppfann den "moderna" konhögtalaren 1925 - vad har egentligen hänt rent principiellt med högtalardesign? Visst har vi elektrostater :mm: och magnetostater :icon_smile_cool: ... men har det hänt nåt mer?

Det jag kommer på är Mangers transducer :closedeyes: som skiljer sig fundamentalt från andra principer.

Kanske kan man nämna piezoelement :Shame On You: och banddiskanter :) också ..

Kombinerade element kom ju också - t ex Tannoys "concentric driver" :shy: .

Vad mer?

:Thinking:

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conan

conan

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Intressant princip. Det liknar den Manger använder, dvs "transversal wave". Skillnaden om jag förstod Podium rätt är att de använder transversella vågor vertikalt medan Manger använder radiella vågor. Trevligt.

Hur låter de?

Edited by conan
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eliot

eliot

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Jag fick detta meddelande när jag klickade på länken: "Sorry, the link that brought you to this page seems to be out of date or broken."

Vore kul att läsa...

//BB

:Praying:

När jag klickar på länken så fungerar den :Thinking:

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conan

conan

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När det gäller tunna högtalare så finns ju NXT och Fraunhofer har tydligen hittat på något, se länk.

Sedan finns det naturligtvis plasma diskant som t.ex Acapella har ;)

Spännande element! Plasmadiskanten har ju 10-20kV mellan elektroderna. Frågan är hur den egentligen låter ... verkar också kunna bli en dyr lösning med RF-elektronik, högspänning osv.

NXT med sina "distributed modes" verkar vara ytterligare en variant av transversella vågor fast mer "slumpmässiga". På en webbsida läste jag att högtalaren genererade ett mer diffust !? ljud så att den inte skulle lida av utsläckningar i rummet som en konhögtalare gör. Det verkar inte helt optimalt att skapa diffust ljud ... men man måste förstås lyssna till dem innan man kan säga nåt egentligen.

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Bebop

Bebop

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Spännande element! Plasmadiskanten har ju 10-20kV mellan elektroderna. Frågan är hur den egentligen låter ... verkar också kunna bli en dyr lösning med RF-elektronik, högspänning osv.

Dom har kanske den renaste diskant som går att uppbringa på klotet idag. Rent och oansträngt och inte på något sätt vasst. Acapella är den högtalare som mest förknippas med plasmadiskanter. Finns bl a hos Eliot.

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Transient Design

Transient Design

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Posted

Nån som vet nåt mer om den "nya högtalartypen" som Anders krönika i senaste H&M talar om? Typ som ett gångjärn fast som tydligen uppfanns (som allt annat?) på 30-talet och tillverkades bla av Siemens och nån mer. Borde fungera bäst för basar tycker jag men klart intressant.

Nån som minns Pheonix Gold som hade en sub-woofer som gick till 11 Hz och egenligen var en propeller kopplad till en elmotor! Lät egenligen inte så dumt men klarade inte så mycket effekt och bara låga frekvenser. Tror vi eldade upp minst en vid prov...

Om vi ändå talar annorunda element så rankas väl även MBL in här med sina lite speciella rundstrålande element?

Jodå, vi har allt räknat på att göra en fullregisters plasma-högtalare! Men den bli inte bara enormt stor, den blir dyr och jäkligt farlig... Ozon är säkert bra men i lyssningsrummet ska det inte vara så mycket!

Mvh Lasse

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plundin™

plundin™

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Jodå, vi har allt räknat på att göra en fullregisters plasma-högtalare! Men den bli inte bara enormt stor, den blir dyr och jäkligt farlig... Ozon är säkert bra men i lyssningsrummet ska det inte vara så mycket!

Fanns det inte en fullregister-plasma på 70-talet?

Plasmatronics!

Plasma Speakers

One day, I’d like to design one of these myself. The "massless" speakers fall into this category ... Ionovac, Magnat, and Plasmatronics (what a name!) They do sound exotic, and measure the same. No resonances at all, and accurate pulse and frequency response up to 100kHz or more. Low distortion too ... like a really good amplifier. Actually, the "diaphragms" do have mass. But it’s not much. It’s the same as the surrounding air, so the acoustic coupling is 1:1. The efficiency is a little difficult to state, though, since the output tubes of the power amplifier are supplying a high voltage that directly modulates a conductive gas with very complex electrical properties.

I first heard the Hill Plasmatronics at the 1979 Winter CES, and I must say I've never heard a tweeter that even came close to that one. The exhibitors darkened the room for dramatic effect, and you could see this weird violet glow through the grill cloth that looked for all the world like a gassy triode ... but it was the tweeter! Not only did it glow, it pulsed along with the music!

The rest of the speaker, though, was a pretty mundane paper-cone setup in a huge cabinet ... oh well. Even so, the Plasmatronics was a wild thing, a taste of the future, like a SR-71 Blackbird in an airport full of commuter-shuttle 737’s. Not too surprisingly, the inventor was a plasma physicist at Los Alamos Labs.

(Talk about being ahead of your time! This was 10 years before the fall of the Berlin Wall, and Dr. Hill was already thinking of ways to peacefully convert atomic swords into sonic plowshares!)

There are a few little problems with this glimpse of Paradise. Previous generations of plasma speakers, such as the DuKane Ionovac tweeter of the Fifties, used RF heating to ionize air, making it conductive. There’s a problem with this. If you ionize air, some of the oxygen molecules (O2) are stripped apart and then recombine as ozone (O3). You also get nitrous oxide (NO2), which is formed by combining nitrogen and oxygen at very high temperatures.

Well, a dose of laughing gas may or may not enhance the listening experience, but ozone really isn’t too healthy, since it irritates and burns the mucous membranes and the eyes. The natural home for these highly reactive gases is far up in the ionosphere, not in your living room.

The Hill Plasmatronics avoided the air pollution hazard by having its own built-in supply of helium, which is a noble gas and thus unreactive even when ionized. Helium is also biologically inert, and being much lighter than air, promptly escapes to the upper atmosphere and outer space. Even in the best-insulated houses it will be gone in a matter of seconds, so it is completely safe.

I remember seeing the helium tank, pressure gauges and all, in a special compartment inside the subwoofer enclosure. Imagine cracking a valve and hearing a very faint hiss of helium gas every time you turn on your hi-fi. Oh, I nearly forgot, you had to swap the helium tank for a fresh one every month. Helium is not a renewable resource, and is only found in a few natural gas wells, so it’s not as inexpensive as other industrial gases.

There are still some interesting plasma-speakers that haven’t been tried yet. For example, one alternative to tanks of helium is a flame speaker (flames are plasmas too), using flammables that release no toxic byproducts of combustion. This leads us to hydrogen and oxygen, preferably generated on-the-spot by splitting water by electrolysis. (You’d water the loudspeaker like a plant!) The hydrogen and oxygen pipes go up to a copper wire mesh (a hemisphere would be the right shape), and the flame is trapped on the surface of the copper mesh.

The system has a computer-controlled power supply that splits the water, monitors the gas flow, and automatically sparks the flame when the correct hydrogen-oxygen ratio is reached. You then polarize the plasma with a high-voltage supply and modulate the flame with a high voltage audio transformer or direct-couple to 211, 845, or 212E plates from the built-in power amplifier. (The flame is modulated in the same way as a conventional electrostatic speaker.)

As far as I know, nobody has ever built a complete system like this before. I hereby throw the idea into the public domain, and wait to see if anybody is crazy enough to actually build it.

Don’t expect to get UL or VDE safety certification for a "loudspeaker" that mixes hydrogen and oxygen gas, high voltage, distilled water, AC power, an open flame, and a microprocessor, all in a domestic environment. Imagine the reaction of the reaction of the insurance company if they discovered how it works!

Aside from these trivial non-audiophile considerations, the plasma-flame speaker would have truly exemplary performance ... very low distortion, perfect impulse response, and a bandwidth of 100kHz or more. Another benefit of the confined-flame speaker is the "diaphragm" can be as big as you want, limited only by concerns like combustion noise, room heating, and fire hazard. As a compromise, a 6" diameter hemispherical flame front certainly wouldn’t be too difficult to build. That would deliver response down to 200Hz or so. It would be lab-standard flat from 200Hz to 100kHz, and no cabinet resonances either.

Just imagine a cold winter’s evening with twin pale-blue flames illuminating the copper-mesh hemispheres, the faint hiss of hydrogen & oxygen gas, the quiet murmuring of the water electrolyzer, and a pair of eighteen-inch-high Western Electric 212E direct-heated transmitter tubes to make it all sing. Add a Jacob's Ladder for visual stimulation and the picture is complete; Bride of Frankenstein has an electrifying night over at Nikola Tesla’s bachelor pad. Careful with that Zippo lighter, Nick!

Från

coneless_speaker.jpg

Se även här

hel.jpg

passionizedspeaker.jpg

Bilderna länkade till stället där jag hittade dom!

Annars var det nog Magnat jag tänkte på..

Only 5 plasma-based audio transducers? (commercially available or at least reviewed)

1. 1950's Dukane Ionofone/IonoVac/Ionofane (later EV)

2. 1979 Alan Hill -- Hill Plasmatronics

3. 1982 Siegfried Klein --

Magnasphere Transpuls MP-X-101 with MP-01 plasma unit

Later models
MP X-066
$8,000, MP X-088 $20,000 (with MP-02 plasma unit). These large units tried to push some real bass!

4. 1983 Nelson Pass -- "Ion Cloud" (Bild ovan!)

5. (current) Acapella Audio Arts/Lanche Audio

Från

/ptr

Edited by plundin
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conan

conan

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Because of the ozone concern, many of the plasma tweeters are illegal in the US. Which is why you don't see much of them today.

...

Nitrogen isn't a good alternative, as you can generate other poisonous compounds when you strike a plasma (which ionizes the gas molecules, making them highly reactive).

Ja, tjena, vätgas som sönderdelas med hjälp av högspänning ... och killen som kommenterade på det forumet oroar sig för "andra giftiga sönderdelningsprodukter" ...

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plundin™

plundin™

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Tack för de intressanta länkarna. Mycket läsvärt. Blev det nåt mer av Nelson Pass högtalare?

...en snabbsökning ger vid handen :

Pass: [laughs] The "Ion Cloud" loudspeaker was another one of those ideas that had kicked around, and the day came when I decided that there was no reason not to build it. As you can see from the photos on the cover of Stereophile and elsewhere, it looked like a large barbecue grill. It had no moving parts and its construction was a grid of wires. We applied some very high voltages to what were, essentially, the tungsten filaments used in photocopy machines. It was really a push-pull electrostat that used ionized gas instead of a diaphragm. And it worked reasonably well. It took several kilowatts to get any sound out of it, but it was the most physically and sonically transparent loudspeaker I've ever run across. That is to say, you could see right through it, and it sounded like it wasn't there. It was quite remarkable in that regard.

We were feeding it with an Ampex tape deck running into our Threshold Model 4000 power amplifier, then driving the loudspeaker through a step-up transformer. It drew so much power at the display at CES that every time there was a loud passage or a transient, the AC line would drop. The tension arms on the tape deck would go slack, the sound would stop, the power would go back up, and it would start again; then the power would go, and it went into an oscillatory loop which included every element of the chain, including the AC line and the tensioning arms on the tape deck. We had a lot of fun doing that—a good demonstration of how much power it required. Fabulous device, but it put out ozone, and after some extensive exposure to the ozone I found myself lacking oxygen in my bloodstream...It was a year before I could go near a copy machine.

Från en intressant intervju med Nelson Pass i Stereophile!

Här kan du läsa "lite" mer om dom...

DiyAudio har många väldigt informerade användare! finns mycket kul att läsa där...

/ptr

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plundin™

plundin™

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Jag fastnade lite i plasmaträsket och började söka efter "Tolteque AHL full range plasma speaker!" Som omnämndes på en av sajterna jag länkade till ovan..

Men haittade bara några omnämnaden att den ställs ut på CES i början av 90-talet, inga bilder men en pdf med en hel del intressant info..

Sedan trillade jag på en engelsk(?) tillverkare "Audio Chambers! mwed en del info, inte minst att dom/han fått patent på en ny plasma/corona-teknik... (Länken till patentet innehåller en full beskrivning och illustrationer!)

Intressant att det fnulas med sånt här ute i stugorna! :D

Här är en pdf till om nån slags (förolyckad) plasmavariant som omnämndes på ännu en av dom länkade sajterna ovan!

/ptr

Edited by plundin
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calle_jr

calle_jr

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Ja, tjena, vätgas som sönderdelas med hjälp av högspänning ... och killen som kommenterade på det forumet oroar sig för "andra giftiga sönderdelningsprodukter" ...

:D :Shame On You:

Aah, den tråden minns jag och ni spelade med EARs monoblock som såg skalmässigt fjuttiga ut i sammanhanget.

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