The Plasmatronic Hill Type 1 Plasma Tweeter + Eminent Technology LFT-8 Loudspeaker

Chief Content Officer Tom Martin had the opportunity to chat w/ Tony Silsich representing Alan Hill's vintage plasma tweeter, helium-fueled loudspeaker design. They touch on Hill's background, the tweeter's unique engineering, its development, and eventual fall into obscurity.
00:00-03:10 The History of Alan Hill's Plasma Tweeter
03:10-06:43 Original Price and Design
06:43-10:23 Why Helium?
10:23-12:10 How Does the Plasma Work?
12:10-13:33 What's the Temperature?
13:33- Is it Going to Make a Comeback?
About Tom Martin:
Tom is a long-time audiophile. He began his reviewing career after acquiring the The Absolute Sound magazine in 1997 and then hi-fi+ magazine in 2002. He has worked closely with Harry Pearson and Robert Harley at TAS and with Roy Gregory and Alan Sircom at hi-fi+. Since Tom and his teams expanded the TAS and Plus platforms in the digital domain, he has served as Chief Content Officer.
What Is The Absolute Sound?
The Absolute Sound magazine has been a leading publication in high-end audio since 1972. Since the early 2000s, The Absolute Sound has expanded to include web, newsletter, digital magazine, social media, KZbin and Substack platforms. The Absolute Sound platforms have a global audience of over 500,000 audiophiles.
Shot and edited by TAS Digital Managing Editor Charles Kinder
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[@falloutlov]

Alan Hill is my Grandfather. He is an inspiration to me and I love him dearly.

[@bolsesolheim7469]

I loved him too !Dr Solheim Norway and Marbella!

[@ChefAnatoly]

This was by far one of the most impressive setups at the 2023 AXPONA show. It felt good to know that such cutting edge audio innovation was being produced around the time that I was born. Not only was the fact that listening to Plasma Speakers was impressive enough, but the sounded amazing. Lots of effortless lush soundstage, clarity, resolution, warm and rich sounding.

[@rocksinger45]

I was lucky to see/hear these speakers back in 1978 at the CES show as I remember it they had a really smooth sound ~ Glad to know these speakers are still around ~ Thanks for this video ~

[@casperdowlen625]

I live in Albuquerque. Back in the mid 1980s I got to listen to these tweeters. Very bizzare but obviously effortless. Just cool.

[@craigellsworth3952]

I heard the Hill Plasmatronics in a store in Dallas back in 1982. One does not need an HP vocabulary to describe what I heard. Simply Wow.

[@James-hb6ee]

I thought the plasma tweeter sounded fantastic, but everything below the tweeter to me sounded slow and wooly. I too heard these at a North Dallas audio dealership, but I don't recall the name of it. I want to say the dealer was located at the intersection of Preston Road and Belt Line Road, but I could be wrong on the location.

[@craigellsworth3952]

@James-hb6ee Hmm, that review pretty much mirrors what HP said about them. What they did right was so overwhelming that pretty much anybody hearing them wouldn't have nit picked the particulars. Except HP, and you. The store was on Alpha Road just west of Hillcrest.

[@dougg1075]

I can see a welding supply company bringing my tanks now. Super cool

[@famousutopias]

For sheer novelty I’ve long thought the Hill Plasmatronics on top and Dayton-Wright electrostatics on the bottom would be a lot of fun, particularly because the D-W required a charge of sulfur hexafluoride in the diaphragm space between the dust covers. Two tanks, great sound!

[@stephenduffy1881]

Amazing technology

[@bolsesolheim7469]

I bought my Plasmatronics from Alans Wife in 1978 ! Still use them in Norway ! Dr Solheim Marbella and Norway!

[@philenns6797]

Thinking way back ... With a few friends, we'd hit different hi-end audio shops around California. A mind blower was that out of all the speakers we'd listen to, the Hill Plasmatronic speaker clearly defined a bass drum pedal squeak on the Bill Evans Quintessence album.

[@charlesnr]

Still remember the original demo with the room full of ozone.

[@plinid]

I am amazed! Not only by the tech & hardware, but also by the love and enthusiasm of this guy! Thank you for this!

[@helmutkool8]

Could you make an follow up and include the differences to the plasma tweeters from Lansche?

[@ccscomments757]

I remember sitting in my high school physics class in about 1980 watching a flame sing. That physics teacher was great.

[@danlearned6199]

The San Diego store he referenced was Ike Issacson's "Audio Directions" in Kearney Mesa. I saw, heard these in the store. Amazing, a pulsating, glowing orb that produced sound. After a while, the ionization effect left a very strong ozone smell to the listening area.

[@c1ferrari]

This is where I heard them as a teenager circa late 70s/early 80s. The sound reproduction from those plasma tweeters was nothing less than scintillating! I recently acquired a green laser and fired it up in the evening sky and experienced that exact sensation of awe.

[@williampearson4968]

I heard the Plasma Tweeter at Axpona 2023 and to me the room was best sound at the show. A wonderful and amazing technology.

[@hermanvisser4034]

Fascinating video. Thanks for posting.

[@poturbg8698]

It's fascinating to see these, BUT WHAT DID THEY SOUND LIKE??

[@jeffglotzer9346]

Brian Beinfang (RIP) had his own pair in the 80's and 90's installed in his dealership, Sound Investments, in Milwaukee WI. They were truly impressive, as the show demo at Axpona this year.

[@snakerog]

I heard them at Audio by Caruso in Miami in the late 70s early 80s time frame. I don't remember them impressing me too much. Seems like the staff was spending more time getting them going than me getting to hear them for any length of time. I also heard and was impressed with a pair of RTR ESR6 tweeters which I bought and enjoyed having and listening to for many years.

[@JohnVander70]

Great story, am very much enjoying your work here on youtube.

[@kevinjackson1370]

Hearing these play the 1812 Overture behind a curtain of speaker cloth at the Chicago CES show so you could see only the flame clearly was a singular moment.

[@julian73de]

Amazing. Never heard of

[@FOH3663]

Amazing times in audio back then ... world class physicsts pushing the boundaries of playback reproduction.

[@glenncurry3041]

Oh the cobb webs are shaking the dust off. But not enough yet! I heard a pair of the original Hill's speakers in someone's home in the S.E. in the late 70's. I was a rep for various lines including Marantz, AR, Kenwood, AT, .... in the S.E. and travelled up to 6 states. I think it was the Atlanta area? But not sure. Could have even been to discuss repping them?

[@eddievega1100]

Star Trek Tech , Scotty would be proud.

[@gzubeck3]

Not having a slot that I can light my $80 cigars with is a deal breaker for me. :>) Why is that all the high end tweeters are dangerous as hell (Plasma and Beryllium). Gives new meaning to "Audio to die for!"

[@jjackson409]

I worked for Lee Terell, Audio Excellence SF, back then. The Twitter is the most natural sounding I have ever heard. No artifacts, just pure bliss. the speed and purity made it hard to match other drivers. would love to have heard it with the ET speaker pairing.

[@zilipoper]

kzbin.infoTNZfHpKWnBs plasma + subwoofer

[@pervertedalchemist9944]

Helium fueled loudspeaker?! You just know someone is going to try to push the limit on those.

[@johnarango7500]

So, just before Hill stopped selling the Plasmatronic, I was contacted about making the cabinets--partly because I was making them for Sound ideas, a local hi-fi store, run by Loren Bishop, who left Sandia Labs to sell Klipsch speakers. Never did build one because Hill decided, as mentioned in the video, to give up the speaker business.

[@stewartashton6997]

Hi John, I worked as a salesman at Sound Ideas from the mid to late 70's. I'm sure our paths must have crossed.

[@db029936]

In canada, the German company Magnat sold plasma speakers for $4000 cdn. A three way tower with plasma tweeter. My friend bought a set. Like those ones in the video, they hissed.

[@db029936]

That was in the seventies.

[@glennbaxter4507]

I heard these at an early '80s CES and tried to talk my boss into meeting with them to discuss representing them in AZ, NM and NV. He wouldn't go to the meeting. He was probably right.

[@janbenschop7597]

I've always thought it was a good way of making a massless driver. Trick is keeping it cool.

[@diwa2601]

I have one type 1 tweeter from local recycle yard and box of parts from another one. P.S. With active Xover user manual ....

[@dougg1075]

I wonder how AI will or could effect the industry. You may be able to have a conversation with your preamp. Or could it design new drivers , crossovers , cabinets etc. I saw a TED where this company used mashing learning to design the frame for a drone, and after millions of iterations and evolutions it spit out the design. It looked nearly identical to a flying squirrel’s skeleton. Very organic looking. And this was several years ago.

[@scottyo64]

My home town gets mentioned and it had nothing to do with crime! 🎉🎉🎉🎉🎉🎉🎉

[@andrearibi932]

Hello … I was debating with a friend the tech …. My friend claims they sound better Can I kindly ask you if you are able to run tests on these and show us with tangible proof ( you know like Klippel .. or mlssa ) the usual proof I hope you have access to the right tool , otherwise there is a couple of guys in the USA that would gladly run them for you I understand this is rare stuff and all , but since you are a commercial venture .. it will be super important for us consumer to verify they claimed superiority to say a dome or ribbon tweeter This is by no mean a ruse or a passive attempt to discredit anything … we just want to understand their strength from a verifiable and scientific perspective

[@raybudau9920]

Didn't also Magnat in Germany have the same thing.

[@sceptor3893]

If your W.A.F is low now, try dragging a 6ft cast iron tank into your living room.

[@JohnLee-db9zt]

If only ozone problem was solved with these speakers.

[@alanhillsplasmatweeter7318]

It is solved since they do not create any ozone - the plasma is extremely hot and destroys ozone, unlike 'cold' discharges.

[@michaelanzelino5068]

Is it true that a man brought one of these units home and three days later, the whole family disappeared. nothing else was disturbed, but the family up and disappeared.

[@user-zq9bn8wo1h]

I think I saw them on From, they’re trying to figure a way out 😂

[@joppepeelen]

lets not forget,,, the helium prevents corosion and less ozone... witch can be lethal

[@a4kata655]

blsht :)))

[@kloss213]

Ozone its what happens.

[@fonkenful]

Yeah, what could possibly go wrong?

[@richardelliott8352]

@@fonkenful I walked into the end of a demo of one of these speakers in San Diego, the room reeked of ozone. Because of the ozone hazard , the speaker was withdrawn from the market the next week.

[@fonkenful]

@@richardelliott8352 I can recall attending VSAC 2003 where Josh Stippich (ElectronLuv) demonstrated an absolutely insane high powered SET with GM100 transmitter tubes running at 1900V, and radiating sufficient ozone that more than 5minutes in the room left one affected by far more than the sound. How he got away with it is beyond me.

[@Secession1900]

Unlike numerous other plasma tweeters like the Ionovac, the Hill tweeter does not ionize air, it ionizes helium, therefore it should not produce ozone in normal operation. I heard the Hill speaker at Axpona 2023 and could not smell any ozone in the air after it had been operating for several hours. If you detected ozone at a demo of the Hill speaker it was broken.

[@guywhite1004]

Ozone is detectable by smell at very low concentrations (~ 0.1 ppm) which is lower than most ozone detectors can detect. The problem is that even at low concentrations the nose becomes insensitive to it to the point where higher concentrations of ozone do not register. This can lead to very bad breathing problems and even death as the ozone concentration increases. Ozone detectors must be used in areas where ozone is used to alarm people that the concentration has risen to dangerous exposure levels. Been gassed by ozone several times - it is not fun.