Electrostatic speakers?

[Blumlein 88]

I agree that most ESLs have a distance from the wall they like. Most seem to be around 5 to 6 feet. And I wonder about the backwave. If listened in mono pointed straight ahead, the backwall reflection will be quite different vs normal stereo use where the backwave is likely at an angle plus near a side wall and will reflect differently into the room.

 

[Duke]

I agree that most ESLs have a distance from the wall they like. Most seem to be around 5 to 6 feet. And I wonder about the backwave. If listened in mono pointed straight ahead, the backwall reflection will be quite different vs normal stereo use where the backwave is likely at an angle plus near a side wall and will reflect differently into the room.

Excellent point - I hadn't thought of that!

 

[Ron Texas]

I agree that most ESLs have a distance from the wall they like. Most seem to be around 5 to 6 feet. And I wonder about the backwave. If listened in mono pointed straight ahead, the backwall reflection will be quite different vs normal stereo use where the backwave is likely at an angle plus near a side wall and will reflect differently into the room.

I don't have that much room nor do most people.

 

[Newman]

I think the only ESLs used in Harman tests were the Quad ESL63 and one of the Martin-Logan hybrids with a woofer. Maybe I'm remembering wrong, but it seems one odd result with the Quad was it did poorly in mono test, but it was used in some of the stereo tests and was closer to other good box speakers. All speakers doing better in stereo blind tests, but the improvement in the Quad was larger.

I see Axo1889 had already posted about this.

This has been discussed numerous times, and it is not the correct interpretation of the relatively bunched up stereo preference scores.

I am confident that you and Axo have both come across these prior discussions, yes?

I am not sure why people are sticking to this mistake, unless it is the usual problem: "It doesn't comply with my sighted listening impressions".

 

[Blumlein 88]

I still need to do the experiment where I put a second Revel behind the first facing to the rear and out of phase. Create a dipole so to speak.

 

[Blumlein 88]

This has been discussed numerous times, and it is not the correct interpretation of the relatively bunched up stereo preference scores.

I am confident that you and Axo have both come across these prior discussions, yes?

I am not sure why people are sticking to this mistake, unless it is the usual problem: "It doesn't comply with my sighted listening impressions".

Well as I recall the largest factor was that all speakers scored better in stereo and were not as well discerned as different. Mono was more discriminating. I don't recall the idea being wrong that stereo listening is more forgiving in which case any speaker with FR and directivity issues were not as clearly inferior. So yes, maybe in stereo listening combined with sighted listening impressions the issues with panels are not as bad as we might think. Same could be said of any speaker, and is not the same idea that it vindicates the issues with panels.

 

[Newman]

No sir, a million miles away from an acid test....
Those preference "scores" are simply means of statistical distributions from the population of folks involved.

Even if those scores, for that limited population, are dead on accurate for preferences of the whole world......

....does that mean I've got a bad speaker cause it scores a few standard devs away from the mean preference?
Or I have a bad brain cause it scores a few standards devs away?
Not saying I'm anything special, but I'd prefer to keep my own mellon, than trade it for the mean

None of that: it just means you are doing sighted listening and your biases are overwhelming your assessments. Which is normal.

Remember this: panel speakers routinely win preference tests in sighted listening.

The fact that the same panel speakers in the same room/setup suddenly drop to less preferred when the test is controlled for non-sonic biases, shouldn't be a trigger for a flood of the usual excuses ("Were they my wonderful panel speakers? Were they set up exactly right?").

None of that matters. Those factors were nulled. But sighted they win, unsighted they lose. It shouldn't be that hard to 'get it'.

But it is. And we all know why: "I will only accept controlled test findings that confirm my sighted listening impressions."

cheers

 

[Newman]

Well as I recall the largest factor was that all speakers scored better in stereo and were not as well discerned as different. Mono was more discriminating. I don't recall the idea being wrong that stereo listening is more forgiving in which case any speaker with FR and directivity issues were not as clearly inferior. So yes, maybe in stereo listening combined with sighted listening impressions the issues with panels are not as bad as we might think. Same could be said of any speaker, and is not the same idea that it vindicates the issues with panels.

The correct interpretation is: the speakers aren't "doing better" in stereo, it's just that the test is "doing worse". ie the stereo test isn't a good enough test to tell us anything about whether the speakers are "doing better" or not.

 

[Blumlein 88]

The correct interpretation is: the speakers aren't "doing better" in stereo, it's just that the test is "doing worse". ie the stereo test isn't a good enough test to tell us anything about whether the speakers are "doing better" or not.

Would be interesting to do the mono test with a corner placement for the ESL and same placement for the box speaker. I think it is easier to live with your sighted bias with panels because the sight is much more different than if it were a box.

 

[MattHooper]

Those are the only ones I'm aware of.

Hybrid electrostats like the Martin Logan are especially demanding of how they are set up. Here's one of the challenges: Sound pressure level falls off at 6 dB per doubling of distance from a point-source (which the woofer approximates), but at only 3 dB per doubling of distance from a line source (which the panel approximates). So listening distance matters, and arguably the ability to adjust the level of the woofer relative to the panel can "make or break it" with a hybrid electrostat. Personally, I would not have chosen the Martin Logan Quest (I think that was the model) as ambassador for electrostats.

Ime electrostats benefit from making good use of their backwave energy, which imo implies that their backwave energy's spectrum not be significantly altered; that it arrives neither too soon nor too late; and that the reflections be neither too loud not too soft. Imo this is just the nature of the beast. And I realize that others have reached different conclusions about what to do with the backwave energy.

I have owned both Martin Logan Quests and Quad "USA Monitors", the latter being a version of the ESL63. I didn't have much test equipment back then (30 years ago), but to my ears the Quads had a couple of tonal balance issues. I spent a lot of time and money trying to remedy those issues rather than quickly moving on to something else because imo what they did well, they did very well. I finally got good tonal balance largely thanks to an equalizer that cost almost as much as the rest of my system combined. Eventually I started looking for a more "elegant" solution, and went in a different direction.

I've mentioned before that though I loved the Quads I grew dissatisfied with the lack of density and "punch" to their sound, and that even smaller stand mounted speakers I'd try seemed more dense and punchy. I got the Gradient dipole subs made specifically for the 63s (which made for a decidedly 2001-like monolith appearance). Interestingly though they were the best sonic match I've heard between a stat and woofer, the dipole subs also seemed to match somewhat the Quad's own "lack of punch" factor. They never did "slam" like the regular floor standing box speakers I replaced them with. This lack of punch vibe is something I always hear with dipoles (which in my experience has been almost always panel speakers, so I'm lacking experience no doubt).

Anything to this?

 

[Duke]

I still need to do the experiment where I put a second Revel behind the first facing to the rear and out of phase. Create a dipole so to speak.

Very interested to hear your impressions!

Here is what I'd suggest:

1. Connect them in the SAME polarity ("bipolar" rather than "dipolar")

2. Place them side-by-side with one facing forwards and the other backwards, rather than one behind the other; and

3. Try plugging the ports on the rear-facing speaker, and maybe even on both speakers. Balled-up socks are probably adequate; this isn't rocket surgery.

Here is my reasoning:

1. In a dipolar configuration I think you'll have too much bass cancellation. Try it and see.

2. When I've modelled bipolar speakers, the net frequency response gets worse the narrower and deeper the enclosure gets. This is why the Mirage M1 was wide and shallow.

3. Below the baffle-step frequency the rear woofer's output "wraps around", and at some point the wavelengths become long enough that the rear woofer's output starts arriving "in-phase-enough" to significantly reinforce the front woofer. So you may end up with too much bass energy if all the woofers are outputting bass at full power. You may end up with too much bass anyway, as the speaker was "voiced" without the expectation of any wrap-around energy.

(here is an arguably relevant online article by yours truly; some ideas expressed therein are outdated.)

I've mentioned before that though I loved the Quads I grew dissatisfied with the lack of density and "punch" to their sound, and that even smaller stand mounted speakers I'd try seemed more dense and punchy. I got the Gradient dipole subs made specifically for the 63s (which made for a decidedly 2001-like monolith appearance). Interestingly though they were the best sonic match I've heard between a stat and woofer, the dipole subs also seemed to match somewhat the Quad's own "lack of punch" factor. They never did "slam" like the regular floor standing box speakers I replaced them with. This lack of punch vibe is something I always hear with dipoles (which in my experience has been almost always panel speakers, so I'm lacking experience no doubt).

Anything to this?

I used the Gradient "subs" too, and agree with your observations. More on that in a paragraph or two.

To my ears the tonal balance of the Quads was light in the bass and they had too much energy in the lower treble region, resulting in harshness on female vocals. Arrrgh! I tried a passive notch filter; added the Gradients to hopefully make the upper treble bumpage less audible; tried an active notch filter (switchable in the active crossover that came with the Gradients); paid someone in California fairly big bucks to upgrade them; added homemade wings; and finally broke down and bought the Cello Palette.

I never heard "slam" with the Gradient subs, but they were imo a nice improvement in tonal balance anyway.

I don't really know why dipoles don't have "slam". I speculate that it's mainly because dipoles inherently do not pressurize the room, and perhaps partially because the high electrical "Q" of a dipole-friendly woofer (and whatever its equivalent would be in an electrostatic or planar magnetic panel) arises from an unusually low motor strength, and ime there is a correlation between motor strength and "slam". If you ever eyeballed the magnets on those Gradient subs, they were pretty small. At best I think they'd hit like a pillow.

 

[AdVis]

One remark about the ESL57, I see people connect all sorts of amps to them and I think that is a bad idea. Yes it's easy to damage an electrostat but that became quickly apparent with the ESL57 and almost all but the first series now have an extra circuit that protects the treble panels. There was a retrofit for the first models and I would expect a restored model would be fitted with it.

Also, the amp of choice for these speakers is the Quad 303 that is more or less designed to drive ESL57's. It can deal perfectly with the weird impedance curve and it is limited to 30 Volts. I regularly see these amps still offered for quite reasonable prices. Granted, it is rated for only 2x15Watts but that is plenty for the ESL57, more is overkill(!) anyway.

They blend perfectly with dipole subwoofers like Ripoles, I can certainly enjoy the infamous "Funkenspelunkin" but indeed with dipole woofers you don't need to replace all the crockery in the cupboards and since I live in an apartment, I don't have a crowd of neighbours brandishing torches and pitchforks outside my front door.

As with every kind of dipole, they do need room to breathe. The layout of my apartment allows me to place them with large spaces behind them and that may not be possible everywhere. And they do have that "head in a vice" sweet spot, but the sound quality is acceptable for casual listening outside that sweet spot. If I then really want to listen to an album, the sweet spot is perfect. I don't see the point of "perfect sound in the kitchen" as I have other things to focus on in there anyway.

The ESL57 was originally designed as a mono speaker "offering a window on the stage as seen from the balcony". That does not work for stereo in a modern living room and allegedly Peter Walker recommended to "place them on a beer case". The dimensions of 2x12" Ripoles certainly come close to that!!

Actually placing the ESL57 as in the promo picture will make sure it doesn't sound any better than a small portable radio but that carpet would drive me nuts anyway.

Incidentally my ESL57's were found in a thrift store by my girlfriend "Look at those funny vintage looking things there." When I heard the EUR 500 price tag I had to pick up my jaw from the floor again. I will get them restored some time but for the moment they are still fine.

 

[Hayabusa]

Also, the amp of choice for these speakers is the Quad 303 that is more or less designed to drive ESL57's. It can deal perfectly with the weird impedance curve and it is limited to 30 Volts. I regularly see these amps still offered for quite reasonable prices. Granted, it is rated for only 2x15Watts but that is plenty for the ESL57, more is overkill(!) anyway.

50Watts it is

 

[gnarly]

None of that: it just means you are doing sighted listening and your biases are overwhelming your assessments. Which is normal.

You presume too much Newman.

You have no idea how many concurrent systems I keep running, systems that are quite different in how they interact with the room/environment, and how they sound.

I value both objective and subjective. I value both blind and sighted listening.
I love audio.
I do not like debates about audio that polarize discussions, and imo are mainly about egos being right.
Pls leave me out of any of your phycological projections.
You provide a lot of good technical info, don't want to have to ignore you. Thanks.

 

[dasdoing]

I would love to hear a "laser beam" system. I use a horn PA speaker that has a very thin vertical, but the horizontal is relatively wide and it's already fascinating how deep you get into the space, can only imagine what a laser beam speaker could do.

 

[Newman]

You presume too much Newman.

You have no idea how many concurrent systems I keep running, systems that are quite different in how they interact with the room/environment, and how they sound.

I value both objective and subjective. I value both blind and sighted listening.
I love audio.
I do not like debates about audio that polarize discussions, and imo are mainly about egos being right.
Pls leave me out of any of your phycological projections.
You provide a lot of good technical info, don't want to have to ignore you. Thanks.

Looks like you took offence, gnarly. I apologise if you took my post as having an objectionable tone, but it wasn’t intended.

You did ask questions, and I attempted to answer them, using the best available science that I am aware of. At no point did I engage in an ‘ego battle’.

But I will point out that everything after the first paragraph of my post was not directed to you personally, but was addressing the general tendency in electrostatic speaker discussions, like most exotic looking and exotic tech hifi, for them to be the subject of positive expectation bias, and numerous posts above mine by numerous members, were hinting that controlled listening tests that don’t rate electrostatics highly must have ‘something wrong with them’, and were trying to pick this or that excuse for enthusiasts to justify dismissing them. I was writing to all of those writers together.

Apologies if it looked like it was all ‘me vs you’.

cheers

 

[Blumlein 88]

Looks like you took offence, gnarly. I apologise if you took my post as having an objectionable tone, but it wasn’t intended.

You did ask questions, and I attempted to answer them, using the best available science that I am aware of. At no point did I engage in an ‘ego battle’.

But I will point out that everything after the first paragraph of my post was not directed to you personally, but was addressing the general tendency in electrostatic speaker discussions, like most exotic looking and exotic tech hifi, for them to be the subject of positive expectation bias, and numerous posts above mine by numerous members, were hinting that controlled listening tests that don’t rate electrostatics highly must have ‘something wrong with them’, and were trying to pick this or that excuse for enthusiasts to justify dismissing them. I was writing to all of those writers together.

Apologies if it looked like it was all ‘me vs you’.

cheers

I didn't take it that way. Plus I agree with you. Nothing wrong with trying to see if you can justify your preference when there are real differences. Not the same as preferring one dac vs another when there is no difference.

 

[MRC01]

I still need to do the experiment where I put a second Revel behind the first facing to the rear and out of phase. Create a dipole so to speak.

Haha well seriously, because dipoles are more sensitive than conventional box speakers to how they are set up in the room, I am skeptical of any direct A/B comparison with other speakers in the same room. The comparison isn't valid unless both sets of speakers being compared are each independently and optimally configured, as well as the listener position.

PS: if both speakers being compared are not in the ideal position, but compromised in order to fit both and perform the test, box speakers will be advantaged since they are relatively less sensitive to positioning.

 

[Justdafactsmaam]

The correct interpretation is: the speakers aren't "doing better" in stereo, it's just that the test is "doing worse". ie the stereo test isn't a good enough test to tell us anything about whether the speakers are "doing better" or not.

Why? The change in preference score changed much more for the Quads in stereo across the board. Stereo is the common usage. How is the test “doing worse?” What unique circumstance in stereo with the Quads causes the test to “do worse?”

 

[dasdoing]

well, let's imagine a speaker with 10 degree vertical and horizontal. a single speaker will have zero "space". a speaker like this will depend totally on the stereo effect to shine