Electrostatic speakers?

[Martini]

I believe the curved electrostatic panel was invented by none other than Roger Sanders. He has since changed his views and manufactures loudspeakers with flat electrostatic panels that are designed to be "beamy."

That's likely do to legal agreements made when he left Martin-Logan and/or patent infringement issues.

I have some Martin Logans and I've enjoyed them. But they are starting to get old and I'm considering replacing them with some Revels. I listened to the 208 & 228-Be at Crutchfield and was very impressed, even in poor setup situation. Would like to hear them at home. However, they are nice chuck of change, especially the Be, and I have a racing hobby/addiction to be mindful of..

 

[Dialectic]

That's likely do to legal agreements made when he left Martin-Logan and/or patent infringement issues.

I think his new perspective is sincere. In many domains, I've found that intellectually honest people change their views over time. Here's a thread on his current (or recent, anyway) thinking.

 

[Frank Dernie]

Dynamic drivers are still better in many ways. The electrostatic sound seems really overhyped when the resting issue on DD's is gone on newer headphones/Speakers. The sweet spot on Dynamic speakers seems to be 2 way or full range with a woofer crossed at 90Hz. The bass on the non dynamic's sound unnatural on Metal, EDM, pop like decay's to fast and sounds like farting when bass boosted, Eg: My ER2XR/DT 770 sound way more clean & natural than the ER4SR in my view. The 4SR was too harsh in the treble & the mids sounded fake from it being quite tin can like at the 1.9 ~ 3.2KHz area.

The durability aspect even more off putting since you can kill LCD's by taking them of your head suddenly.

Headphones and speakers are completely different in the way they interact with both your ear and your room, so no implication can be drawn from headphones in a speaker thread IME.

 

[andreasmaaan]

That's likely do to legal agreements made when he left Martin-Logan and/or patent infringement issues.

I'm not sure what the relevant patent is, but it can't last longer than 20 years in most jurisdictions, so I would guess that if he's using flat panels now, it must be by choice.

 

[Dialectic]

I'm not sure what the relevant patent is, but it can't last longer than 20 years in most jurisdictions, so I would guess that if he's using flat panels now, it must be by choice.

Yes, such a patent is now long-expired in the USA.

By some accounts, the reason the Quad ESL 63 took so long to "develop" is that Peter Walker was waiting for the expiration of someone else's patent on the electrostatic panel with concentric rings to mitigate beaming.

 

[Martini]

Good point about patent life and although they can sometimes be renewed, I would suspect they would find it difficult to gain approval for an extension on this tech. However, the CLS panel could be linked as ML trademark, creating challenges.... Just thinking out loud here. But more likely a legal agreement when the partners split. Mark Levinson lost rights to his name after being bought out; stuff like this happens and Sanders has to make a living. Tonally, is there comprise in the sound, beyond beaming, between a curved and flat ELS? I dunno and don't really care.

 

[anmpr1]

I like them, and have owned them, but overall they have the wrong trade-offs for me.

Quad ESL (original)--sounds first rate at low levels but can't play loud, and beams terribly. Peter Aczel rated it as one of the best speakers of all time. Mark Levinson HQD'd it. Harvey Rosenberg sold specially modified price no object Futterman OTL amps for it. What can you say? My experience with it was with the old 303 amp. I'd like a pair right now.

Acoustat 2+2--overall sound quality not as nice as the Quad, but played louder with lower subjective bass. Impressive at first, but after a while I began to notice a plastic-like quality to the sound. Possibly because that's what the panel was made out of? Needed a powerful amplifier that could pump out the watts into low impedances Beamed terribly. Sounded best at least four feet from any back or side wall, making placement a lot more difficult than the usual box speaker. I have no idea why they went south since the company sold a lot of them, and they were not expensive in the electrostatic scheme of things. Rockford bought them (along with Hafler) and soon it was all over. After Acoustat went south, Jim Strickland, the original engineer, wound up designing the last of the Hafler amps, at least as I understand it.

Beveridge--totally different kind of sonic presentation, like bathing in or being immersed in sound... did not beam so you didn't have to sit with your head in a vice. As big as it was it didn't play very loud. Super tweaky, unobtanium electronics that had a habit of blowing up, as I recall. Weird looking. Funny bass.

Sound Lab--played louder than the Quad, maybe as nice an overall sound. The ones I heard needed a big room. Otherwise you got a 'headphone effect' listening up close.

As good as electrostatics sound, and as much as people like them, they are probably unavailable for accurate Klippelization. Like Replicants, my guess is that if you put the machine on them, they wouldn't pass the test. I'd like to see it though, here at ASR.

 

[Blumlein 88]

I like them, and have owned them, but overall they have the wrong trade-offs for me.

Quad ESL (original)--sounds first rate at low levels but can't play loud, and beams terribly. Peter Aczel rated it as one of the best speakers of all time. Mark Levinson HQD'd it. Harvey Rosenberg sold specially modified price no object Futterman OTL amps for it. What can you say? My experience with it was with the old 303 amp. I'd like a pair right now.

Acoustat 2+2--overall sound quality not as nice as the Quad, but played louder with lower subjective bass. Impressive at first, but after a while I began to notice a plastic-like quality to the sound. Possibly because that's what the panel was made out of? Needed a powerful amplifier that could pump out the watts into low impedances Beamed terribly. Sounded best at least four feet from any back or side wall, making placement a lot more difficult than the usual box speaker. I have no idea why they went south since the company sold a lot of them, and they were not expensive in the electrostatic scheme of things. Rockford bought them (along with Hafler) and soon it was all over. After Acoustat went south, Jim Strickland, the original engineer, wound up designing the last of the Hafler amps, at least as I understand it.

Beveridge--totally different kind of sonic presentation, like bathing in or being immersed in sound... did not beam so you didn't have to sit with your head in a vice. As big as it was it didn't play very loud. Super tweaky, unobtanium electronics that had a habit of blowing up, as I recall. Weird looking. Funny bass.

Sound Lab--played louder than the Quad, maybe as nice an overall sound. The ones I heard needed a big room. Otherwise you got a 'headphone effect' listening up close.

As good as electrostatics sound, and as much as people like them, they are probably unavailable for accurate Klippelization. Like Replicants, my guess is that if you put the machine on them, they wouldn't pass the test. I'd like to see it though, here at ASR.

I think your description of these are accurate. I think the best overall ESL is the Quad Esl63. Best in the sense of managing the various trade-offs in a practical speaker. The overall results were nearly always pretty good.

I think a larger Quad with many more segments would be the best ESL. It could act more closely to a true point source.

 

[watchnerd]

I like them, and have owned them, but overall they have the wrong trade-offs for me.

I think they're also a research backwater.

The amount of R&D dollars and time going into optimizing dynamic speakers has to be an order of magnitude higher than for electrostats.

 

[MattHooper]

Jus an FYI since there seems to be some dated knowledge floating about here. Almost all of the ML Electrostatic speakers are now Hybrid build types. They have also curved the panels to reduce the head in a vice problem.

Yeah they've been curving their panels forever with the claim it helps with the beaming head-in-vise problem. I've listened to a large number of ML speakers and never found it helped really at all. They are still about the beamiest speakers I've heard, with even a slight head movement shifting the sound towards one speaker. I've heard the Sanders designs are even more-so but haven't heard.

 

[MattHooper]

I started with Quad ESL63s, living with just the panels for quite a while. Loved them for all the reasons people have already pointed out. But eventually I became dissatisfied with the "ghostly" presentation I find form all electrostatic speakers. It's like "seeing" images of instruments through a portal, but I don't "feel" the sound, as if they are actually moving air in the room. Every time I set up a smaller pair of box speakers to compare, the difference was pretty stark with the box speaker sounding more palpable, dense, dynamic and "air moving." And that was the case even though the box speakers had more limited low frequency range than the ESL.

I did try adding subs, but it only made the range covered by the sub sounding dynamic - the panel portion still had that ghostly detached sound.
Later I added the dipole Gradient subs made especially for the 63s. Best stat/dynamic driver match I've yet heard. Still...didn't have that top to bottom seamless punch and palpability of the average box speaker.

So I moved on. And like almost all who started out with Quads or stats, searched for a box speaker that could get me the best of both worlds - the "disappearing" act of the quads as sound sources, the sense of transparency and fine detail, but with the guts of dynamic speakers.

I found plenty of dynamic speakers that got satisfyingly close to that ideal. But I still love hearing a stat or panel speaker whenever I can. Stats are a lovely place to visit for me, but no longer home.

(Though it's killing me that someone I know actually offered me their ESL 57s for FREE - my favorite panel speaker and one I"d love to have around, but they just wouldn't fit in to my room situation).

I've never found a hybrid stat speaker satisfying, which included hearing plenty of the ML speakers, as I still hear that dynamic discontinuity - put on Rush and it's "rockin'" in the bass where the dynamic sub is covering, but goes all transparent and ghostly in the mids up where the guitars, vocals etc are.

But in no way do I propose my own subjective feelings indict anyone's love of stats or hybrids, as I can totally understand the appeal!

 

[watchnerd]

I've never found a hybrid stat speaker satisfying, which included hearing plenty of the ML speakers, as I still hear that dynamic discontinuity - put on Rush and it's "rockin'" in the bass where the dynamic sub is covering, but goes all transparent and ghostly in the mids up where the guitars, vocals etc are.

Ditto.

I also tried using a sub with hybrids to help the dynamic discontinuity, but that didn't really work, either.

 

[mhardy6647]

Quad ESL (original)--sounds first rate at low levels but can't play loud, and beams terribly. Peter Aczel rated it as one of the best speakers of all time. Mark Levinson HQD'd it. Harvey Rosenberg sold specially modified price no object Futterman OTL amps for it. What can you say? My experience with it was with the old 303 amp. I'd like a pair right now.

Everyone should own a pair of "ESL-57s" (I do) -- or at least spend a good chunk of time listening to a pair.
They are insensitive, incapable of handling much power without damage (panel arcing, particularly the tweeter panel) and have 15 degree vertical dispersion. They also have somewhat limited LF performance.

But the clarity and transparency of what they deliver, even with all of those constraints, is something to experience. I'd (still) consider them an invaluable reference, especially for midrange reproduction.

 

[watchnerd]

Everyone should own a pair of "ESL-57s" (I do)

It's going to be tough for everyone to own a pair of something no longer made.

 

[Harmonie]

Well, there are worse things. Stats on chamber music is certainly the best way to hear chamber music.

Maybe the reason I got to like chamber, Mediaeval, ancient music aso.

After all, could well be that MartinLogan educated me !

 

[egellings]

Didn't dispersion issues get solved with the curved 'stats? I have not heard a curved one and so don't have any personal experience in that.

 

[anmpr1]

Acoustat 'solved' vertical beaming by making the panels about six feet high. So you could stand up and sit, and that part of the image was relatively stable. But you still had the problem of horizontal dispersion, which just wasn't there. I recall moving slightly off axis; it was as if one of the loudspeakers suddenly turned off. Maybe not that bad, but it was definitely a 'one seat' loudspeaker.

To work out the horizontal dispersion they made the Model 3 and 4, which were really wide. But they didn't sound as coherent IMO as the Model 2 variants.

The original Acoustat X featured a direct coupled tube amp supplying high voltage to the panels. But that design was evidently unreliable in the field, and people wanted to use their own amps, so later models had a transformer on the back base of the unit. I found the dedicated Acoustat FET amplifier suitable for driving them.

The last models featured integrated woofers in the base, but didn't really integrate well. It's quite difficult to seamlessly blend a dynamic driver sub to an electrostatic.

 

[anmpr1]

I think they're also a research backwater. The amount of R&D dollars and time going into optimizing dynamic speakers has to be an order of magnitude higher than for electrostats.

As much as I hate to admit it, the forward firing box loudspeaker is for practical purposes the way to go. Especially for typical listening environments.

I've heard good things about minimal baffle speakers such as Siegfried Linkwitz' 521, but you have to really know what you are doing to get involved with that. I mean really know. It's not a 'take it out of the shipping carton and hook it up' solution.

Horns (which I like) and ESLs which I kind of like have their own problems. So they will always be a minority solution. If I needed another box speaker (which I don't and probably won't buy another at my age) I'd be happy to investigate some of the good ones reviewed here on ASR. Especially the self powered monitors. I think now is a good time to be in market for a small loudspeaker. Practical designs and relatively to downright inexpensive.

 

[mhardy6647]

It's going to be tough for everyone to own a pair of something no longer made.

I own a pair, it wasn't hard.
There aren't that many folks on this forum.
The ESL-57 was in production for a long time.
QED



Plus, there was my addendum -- or at least spend a good chunk of time listening to a pair.

Y'all can come over any time, post-COVID!

PS Just one is OK, too. When they came out, most systems (especially in the UK) were still mono.

 

[watchnerd]

I own a pair, it wasn't hard.
There aren't that many folks on this forum.
The ESL-57 was in production for a long time.
QED

There are 1,051 forum members.

There are 66 entries listed for sale around the world right now, and that includes parts, manuals, and other bits:

https://www.hifishark.com/model/quad-esl-57

In North America, there are a grand total of 9 entries.

Doesn't seem like the supply is high enough for everyone to own a pair.

QED right back at you, buddy.