Electrostatic speakers?

[SIY]

A customer has some Sanders, I would definitely make sure you can hear them ( or any electrostatic) in your own place before purchase.

I listened to them at a show in nearfield. Very one person sweet spot but absolutely glorious in that spot.

Yet another method is symmetrical electrical segmentation, which is only feasible with flat-panel wire-stator designs, but it allows tailoring the dispersion pattern however one likes.

Quad 63/988/989 take that a slightly different way and use PC board stators.

 

[Mikig]

judgment suspended. I have a pair of Martin Logan Quests - I've never been able to find the right position in the room. I searched online on the forum, ML site but nothing. Nothing that has ever made me exclaim about a miracle. Maybe it's the room that's unsuitable, or maybe the system configuration, although I've tried several. I finally gave up….

 

[MRC01]

judgment suspended. I have a pair of Martin Logan Quests - I've never been able to find the right position in the room. I searched online on the forum, ML site but nothing. Nothing that has ever made me exclaim about a miracle. Maybe it's the room that's unsuitable, or maybe the system configuration, although I've tried several. I finally gave up….

Dipoles are more sensitive to room positioning than conventional speakers. To sound their best the room needs to be arranged around them, and not vice versa. This can be a blessing or a curse, depending on one's perspective.

 

[Mikig]

Dipoles are more sensitive to room positioning than conventional speakers. To sound their best the room needs to be arranged around them, and not vice versa. This can be a blessing or a curse, depending on one's perspective.

specifically what do you mean by “the room must be arranged around them”? What precautions do you suggest? Thank you!!

 

[MRC01]

specifically what do you mean by “the room must be arranged around them”? What precautions do you suggest? Thank you!!

I mean dipole speakers radiate equally forward and back, and after the back wave reflects forward it interferes with the forward wave. They rely on that interference being specifically controlled. For example, the Magnepan 3.6/R have a rise in the bass that is expected to be countered by the reflected back wave to give flat response. Thus the distance from the front wall (the wall behind them), the toe-in angle of the speaker, the distance from the side walls, and the composition of the walls, all affect the distance and timing of that reflected wave and significantly change the speaker's response.

With dipoles, you need to experiment and listen (better yet, measure), make changes and repeat in order to dial them in. The speakers must be placed where performance is best, and if you compromise by moving them even a small amount to satisfy room decor or SWMBO (she who must be obeyed), the sound quality suffers.

All speakers are like this to some extent, but dipoles are more sensitive to room setup than conventional speakers. Thus, speaker positioning comes first, room decor is secondary - the room must be arranged around the speakers, and not vice versa.

 

[Sir Sanders Zingmore]

To the best of my knowledge, only the Sanders ESL has a lifetime warranty. The industry-standard is 5 years.

Sanders also offers a 30 day in-home trial.
I’m an owner and my subjective opinion is that, in the (very small) sweet spot they are up there with the best speakers I’ve heard anywhere.

 

[Mikig]

I mean dipole speakers radiate equally forward and back, and after the back wave reflects forward it interferes with the forward wave. They rely on that interference being specifically controlled. For example, the Magnepan 3.6/R have a rise in the bass that is expected to be countered by the reflected back wave to give flat response. Thus the distance from the front wall (the wall behind them), the toe-in angle of the speaker, the distance from the side walls, and the composition of the walls, all affect the distance and timing of that reflected wave and significantly change the speaker's response.

With dipoles, you need to experiment and listen (better yet, measure), make changes and repeat in order to dial them in. The speakers must be placed where performance is best, and if you compromise by moving them even a small amount to satisfy room decor or SWMBO (she who must be obeyed), the sound quality suffers.

All speakers are like this to some extent, but dipoles are more sensitive to room setup than conventional speakers. Thus, speaker positioning comes first, room decor is secondary - the room must be arranged around the speakers, and not vice versa.

fortunately I have no positioning problems. I have a dedicated room so I can do anything!! I tried moving them further away or closer together, positioned further forward or backwards, straight or slightly toe with different amplifiers... nothing, I always feel them a little muddy, and above all I always perceive the music too much on the speaker; they never disappear. So much so that I'm starting to think it would be better to have them serviced to remove any doubts. I also vacuumed the grills, I even wanted to "wash" them as some recommend, but I didn't feel like it. Some, however, recommend always leaving them plugged in: apparently it seems to have a beneficial effect...

 

[Duke]

Imo a primary set-up consideration for dipole speakers is the reflection path length for the back wave. If the backwave energy arrives too early, it is more detrimental than beneficial, and clarity is degraded. Ime 5 feet or more distance to the front wall is desirable, and 3 feet is the absolute minimum. Less than 5 feet and imo one should look into diffusing the backwave energy or otherwise directing it away from the listening area, perhaps by setting the system up along the diagonal of the room, if feasible.

Good set-up is arguably even more complicated for hybrid electrostats (that is, those which combine a dipole panel with a conventional woofer). The tall panel approximates a line source, and the woofer approximates a point source, and sound pressure level falls off more slowly from a line source than from a point source. So the spectral balance changes with listening distance. Ime the ability to adjust the relative levels of woofer and panels and thereby optimize for the primary listening location, such as on the Sanders electrostats, is a worthwhile feature.

 

[MRC01]

... dipole speakers radiate equally forward and back, and after the back wave reflects forward it interferes with the forward wave. They rely on that interference being specifically controlled. ...

Imo a primary set-up consideration for dipole speakers is the reflection path length for the back wave. If the backwave energy arrives too early, it is more detrimental than beneficial, and clarity is degraded. Ime 5 feet or more distance to the front wall is desirable, and 3 feet is the absolute minimum. Less than 5 feet and imo one should look into diffusing the backwave energy or otherwise directing it away from the listening area, perhaps by setting the system up along the diagonal of the room, if feasible.
...

Yep, we're speaking the same language here. Also remember with a dipole the backwave is inverted from the front wave at the speaker source; when the panel moves forward that's a peak for the front wave yet a trough for the backwave, and vice versa. Surprisngly, this phase inversion is commonly overlooked.

For example suppose the speaker has a rise at 55 Hz that you need to cancel with the backwave. 55 Hz has a wavelength of 20', and after the backwave reflects forward we want it offset from the front wave by half a wavelength or 10'. If the speaker is 5 feet from the back wall, the total distance traveled is 10' which is half a wavelength - good right? No! Since the backwave is inverted at the source, a half-wavelength shift like this puts it in phase with the front wave which is the opposite of what you want! Due to the phase inversion you need that reflected distance to be 20' or a full wavelength. So the speakers need to be further out in the room. But not necessarily a full 10' from the front wall, because you can toe them in, which angles the reflection making it take a longer path before reflecting forward. This gets complex because the angle and the distance to side walls now plays a role.

Anyway, this is just one example at 55 Hz. If the peak frequency to cancel is 110 Hz then you halve these distances. The point remains that dipoles need to be away from the room walls, positioning is critical to performance and simple wavelength calculations aren't always possible because the reflections get complex. It requires experimentation and careful listening or measurement to get it right.

 

[Sir Sanders Zingmore]

Ime the ability to adjust the relative levels of woofer and panels and thereby optimize for the primary listening location, such as on the Sanders electrostats, is a worthwhile feature.

Agree with this. Sanders electrostats integrate the panel and woofer via a digital crossover. This allows for a very steep crossover as well as time alignment (as well as EQ to linearise the panel). To my ears the integration is seamless.
I *think* the newer Martin Logan’s now have a digital crossover. I’ve not heard them but the older versions that I have listened to, sounded to me, much less integrated.

 

[Jazzman53]

I listened to them at a show in nearfield. Very one person sweet spot but absolutely glorious in that spot.

Quad 63/988/989 take that a slightly different way and use PC board stators.

I stand corrected... you are right, the Quads did use electrical segmentation with concentric ring conductors!

 

[Newman]

Curved panels solve the beaming problem.

When you say solve, do you mean “looks solved”, or “measures solved”, or even “Martin Logan says solved”?

Because Dr Sean Olive, PhD career audio researcher and ASR-badged Technical Expert and Audio Luminary, says (in effect) “not solved”. Or to quote him verbatim on Martin Logan’s curved electrostatic panels, “The speaker is very directional and the balance changes as you move off-axis.”

cheers

 

[dlaloum]

When you say solve, do you mean “looks solved”, or “measures solved”, or even “Martin Logan says solved”?
View attachment 362542

Because Dr Sean Olive, PhD career audio researcher and ASR-badged Technical Expert and Audio Luminary, says (in effect) “not solved”. Or to quote him verbatim on Martin Logan’s curved electrostatic panels, “The speaker is very directional and the balance changes as you move off-axis.”

cheers

The Quad ESL63 (and later) delay line design, that makes the speaker simulate a "pulsing sphere" of sound, helps with resolving much of that... but you still need to design the room around them and cater for the back wave reflections as well as the direct sound.... - the resulting "image" is not as sharp as what can be achieved with a more standard panel (such as the ESL57) - but you still have very good imaging and over a wide listening area (and if correctly placed, with the backwave properly leveraged you can get a massive soundstage as well)

 

[Sir Sanders Zingmore]

When you say solve, do you mean “looks solved”, or “measures solved”, or even “Martin Logan says solved”?
View attachment 362542

Because Dr Sean Olive, PhD career audio researcher and ASR-badged Technical Expert and Audio Luminary, says (in effect) “not solved”. Or to quote him verbatim on Martin Logan’s curved electrostatic panels, “The speaker is very directional and the balance changes as you move off-axis.”

cheers

Sanders takes directionality and runs hard with it. They are deliberately designed to beam as *much* as possible

Sanders Sound Systems Model 11

3d3a.princeton.edu

 

[Jazzman53]

Here's some more directivity sonograms comparing an unsegmented flat panel, a 30-degree arc curved panel, and a symmetrically segmented panel. This came from a post by Steve Bolser on the DIY Audio Forum, which I copied on my website.

 

[Blumlein 88]

Here's some more directivity sonograms comparing an unsegmented flat panel, a 30-degree arc curved panel, and a symmetrically segmented panel. This came from a post by Steve Bolser on the DIY Audio Forum, which I copied on my website.

I had hoped by now someone would take the segmented time delayed approach of Quad and make a modern large panel version with more segments in it. One could make a terrific ESL this way. Or a line source with vertically segmented panels would be an easier to build approach.

I've had lots of ESL's. The worst for head in a vice were Acoustat Twos. These actually had two panels at a small angle to each other. The Acoustat 3's were three panels in an arc and were much better. Old Quads weren't horrible as they had a tweeter and woofer panel. Soundlabs with an arc were better. The Quad ESL-63s were best in terms of being usable over a wider area. Sanders were pretty much a one spot listener position. As were 1+1 Acoustats. Heard some M-L's and others too.

 

[Jazzman53]

I had hoped by now someone would take the segmented time delayed approach of Quad and make a modern large panel version with more segments in it. One could make a terrific ESL this way. Or a line source with vertically segmented panels would be an easier to build approach.

I've had lots of ESL's. The worst for head in a vice were Acoustat Twos. These actually had two panels at a small angle to each other. The Acoustat 3's were three panels in an arc and were much better. Old Quads weren't horrible as they had a tweeter and woofer panel. Soundlabs with an arc were better. The Quad ESL-63s were best in terms of being usable over a wider area. Sanders were pretty much a one spot listener position. As were 1+1 Acoustats. Heard some M-L's and others too.

This isn't specifically the Quad approach, insofar as it's powered thru an RC line rather than an LC line, but it's a symmetrical 15-segment (7+1+7) quasi-line source panel with good dispersion and it sounds pretty incredible. Full details here: https://jazzman-esl-page.blogspot.com

 

[Blumlein 88]

This isn't specifically the Quad approach, insofar as it's powered thru an RC line rather than an LC line, but it's a symmetrical 15-segment (7+1+7) quasi-line source panel with good dispersion and it sounds pretty incredible. Full details here: https://jazzman-esl-page.blogspot.com

I've read that and it looks terrific. Too bad there isn't a commercial product built that way. Some nice work there that you did.

 

[Da Capo]

I've had a pair of Acoustat Model 3's since the 1970s (I don't remember exactly when I got them). The Acoustats replaced a pair of IMF Reference Standard Professional Monitors Mk IV. Those were large box speakers, with transmission line loaded woofers. Very different sound presentations. The IMFs had terrific bass extension, and created a soundstage that was small but deep and precisely layered. It was a bit like the sonic equivalent of a 3D movie on a small screen. The Acoustats create a more diffuse sonic image, not as precise, but more like the experience of music in a large space.

Both speakers were enormously enjoyable, and the Acoustats are still going strong. I think we tend to become accustomed to the sound of a loudspeaker, and our brains fill in the features that might be missing from the sound. On the (now infrequent) occasions when I visit a HiFi store, the other speakers usually sound "wrong" to me.

By the way, here's a guy with a similar taste for sound. Great minds think alike, eh?

https://heymanreference.be/747/steve-jobs-long-lost-stereo-system/

 

[Blumlein 88]

I've had a pair of Acoustat Model 3's since the 1970s (I don't remember exactly when I got them). The Acoustats replaced a pair of IMF Reference Standard Professional Monitors Mk IV. Those were large box speakers, with transmission line loaded woofers. Very different sound presentations. The IMFs had terrific bass extension, and created a soundstage that was small but deep and precisely layered. It was a bit like the sonic equivalent of a 3D movie on a small screen. The Acoustats create a more diffuse sonic image, not as precise, but more like the experience of music in a large space.

Both speakers were enormously enjoyable, and the Acoustats are still going strong. I think we tend to become accustomed to the sound of a loudspeaker, and our brains fill in the features that might be missing from the sound. On the (now infrequent) occasions when I visit a HiFi store, the other speakers usually sound "wrong" to me.

By the way, here's a guy with a similar taste for sound. Great minds think alike, eh?

https://heymanreference.be/747/steve-jobs-long-lost-stereo-system/

He had them much too close to the wall while having plenty of space to move them out. Was my first thoughts when I first saw that picture.