Electrostatic speakers?

[Duke]

Certainly if you have to hear the room you don’t want it to act as a passive equalizer.

I think we're pretty much on the same page here.

I still think the better solution is to kill the room. That will result in hearing less of the room.

"Kill the room to hear less of the room" makes intuitive sense, but arguably can have downsides. Imo an alternative approach is "work with the room".

I'll go out on a limb here and speculate that you'd prefer to hear the spatial signature on the recording rather than the spatial signature of the playback room.

If so, then you and I simply have different ideas about the best way(s) to go about accomplishing that.

 

[Justdafactsmaam]

"Kill the room to hear less of the room" makes intuitive sense, but arguably can have downsides. Imo an alternative approach is "work with the room".

What do you think are the downsides?

I'll go out on a limb here and speculate that you'd prefer to hear the spatial signature on the recording rather than the spatial signature of the playback room.

Absolutely

If so, then you and I simply have different ideas about the best way(s) to go about accomplishing that.

Quite possibly. My approach is highly directional low distortion speakers, kill the room, use the BACCH cross talk cancellation SP.

 

[dlaloum]

But they do, there is a very thin mesh on the rear stators of all > 63 panels..

Hah I was not aware of that...

 

[dlaloum]

5 to 6 feet is the distance-from-the-wall recommendation I arrived at experimentally many years ago, and later I met Earl Geddes and began reading David Griesinger, and they both recommend 10 milliseconds reflection-free interval after the arrival of the direct sound, which corresponds to the time it takes for the backwave to arrive after bouncing off a wall 5.5 feet behind the panels. (With most dipole electrostats, the effective reflection-path-length distance would be increased if the speakers are toed-in significantly).

About fifteen years ago I started to incorporate rear-firing tweeters in my own speaker design, which imposed a reflection-path-length requirement that called for positioning the speakers fairly far out from the wall. I didn't want to impose this requirement on my customers so I started aiming the rear-firing tweeter either upwards or up-and-back at an angle, which resulted in a considerably longer reflection path length. Imo it seems to work - it seems to give the intended benefits while allowing the speakers to be placed much closer to the wall than would normally be acceptable.

This leads me to wonder whether a large enough waveguide could re-direct the backwave of an electrostat in a way that allows closer-to-the-wall placement than we can normally get away with. Harold Beveridge used waveguides in his (imo brilliant) electrostat designs, but he used them for the frontwave. Unfortunately a dedicated backwave waveguide would increase the "visual mass" of the speaker considerably, even though the net result might be less real estate being effectively occupied by the speakers.

Depending on the room layout and size, you can place them closer to the walls by angling... as soon as you angle them inwards towards the MLP, the back wave, then bounces off the back wall, then the side wall, before coming back into the center of the room ... which allows for a 1m /3ft distance from back wall...

 

[dlaloum]

Peter Walker was a genius not a fool.
His white papers on the design are available still from the 1950's Wireless World magazine.

If he could have 'got away' with building a speaker with one panel he would not have produced the 63 with four panels and the 989 with six panels.
Do you think he didn't try smaller first ?

That's how panel speakers work, very low but fast output over a large surface area.

So to reduce this to the size of a shoe box and push it up against a wall - must be magic.

Few people wish for loudspeakers the size of a door including me, that is why I bought the Martin Logan Electromotion which also claimed magical things, turned out the magic was just a marketing trick.

I believe the 989 was produced after the Walker era..., and they basically doubled the number of bass panels - which also raised the treble panels... I owned a pair of 989's for a few years.... enjoyed them hugely.

 

[Duke]

What do you think are the downsides?

The apparent preference for wide-and-uniform pattern speakers in controlled blind listening indicates that a fairly well-energized and spectrally-correct reflection field is generally desirable from a sound quality standpoint.

Very often "kill the room" involves aggressive use of absorption, and absorption tends to be more effective at short wavelengths than at longer ones. So unless the absorption is truly broadband, what can happen is that the spectral content of the reflections is drastically altered. The ear/brain system looks at the spectral content (specifically the overtone patterns) to correctly identify reflections as such. This can be the result: At some point before it decays into inaudibility, the reflections lose so much of their overtone content that they are no longer identifiable as "signal" and become "noise".

Imo better to start out with sufficiently narrow-pattern speakers to begin with, rather than relying on absorption that significantly alters the spectral content of the reflections.

My approach is highly directional low distortion speakers, kill the room, use the BACCH cross talk cancellation SP.

Sweeet!! Do you have Janszens?

I am not certain that what works best with the BACCH system also works best for conventional two-channel. My understanding is that some in-room reflection energy is okay with the BACCH system as long as it is quite late-arriving and/or de-correlated (this based on e-mail exchanges with Dr. Choueri).

Let me ask you this, if you don't mind, since you have real-world experience with the BACCH that I lack:

If you were looking specifically for a loudspeaker with a radiation pattern that was optimum for the BACCH, what would you look for?

Depending on the room layout and size, you can place them closer to the walls by angling... as soon as you angle them inwards towards the MLP, the back wave, then bounces off the back wall, then the side wall, before coming back into the center of the room ... which allows for a 1m /3ft distance from back wall...

Yes! I didn't go into detail about that, but you are right.

 

[Justdafactsmaam]

The apparent preference for wide-and-uniform pattern speakers in controlled blind listening indicates that a fairly well-energized and spectrally-correct reflection field is generally desirable from a sound quality standpoint.

This is a subject worthy of its own thread. I don’t think this conclusion is as solid as is commonly believed on this forum

Very often "kill the room" involves aggressive use of absorption, and absorption tends to be more effective at short wavelengths than at longer ones. So unless the absorption is truly broadband, what can happen is that the spectral content of the reflections is drastically altered. The ear/brain system looks at the spectral content (specifically the overtone patterns) to correctly identify reflections as such.

Absolutely. But when it is broadband it does the trick. I’m rebuilding my dedicated room as we speak. The absorption is extremely broadband.

This can be the result: At some point before it decays into inaudibility, the reflections lose so much of their overtone content that they are no longer identifiable as "signal" and become "noise".

Dead rooms have lower noise floors. Low level signals are more easily heard as signal.

Imo better to start out with sufficiently narrow-pattern speakers to begin with, rather than relying on absorption that significantly alters the spectral content of the reflections.

I’m opting for both

Sweeet!! Do you have Janszens?

No. But I have heard them a few times. I was very impressed

I am not certain that what works best with the BACCH system also works best for conventional two-channel.

I’ve preferred less room sound prior to using the BACCH. I think it’s a point of debate. There are serious experts on both sides of this fence. JJ advocates the idea that the best room is no room as well as Ethan Winer.

I don’t want this to decay into an expert pissing contest with the usual ASR suspects. But I think it’s fair to say it’s a point of legitimate disagreement

My understanding is that some in-room reflection energy is okay with the BACCH system as long as it is quite late-arriving and/or de-correlated (this based on e-mail exchanges with Dr. Choueri).

It’s “ok” but the ideal is a dead room.

Let me ask you this, if you don't mind, since you have real-world experience with the BACCH that I lack:

If you were looking specifically for a loudspeaker with a radiation pattern that was optimum for the BACCH, what would you look for?

The Sanders 10Es. That is what I have. It is also what Edgar uses as a reference. They are very narrow dispersion from 150 hz up. One of the knocks on them have been the “head vice” narrow sweet spot. With the BACCH head tracking the “head vice” effect is completely eliminated. Eliminated in ways that can’t be achieved without the head tracking with two channel stereo no
Matter how wide the dispersion of the speakers.

 

[Newman]

This is just battling opinions. No data?

 

[Justdafactsmaam]

This is just battling opinions. No data?

Edgar and his research team at Princeton have done a great deal of actual scientific research on this and other subjects. He has plenty of data in support of his findings. It’s real science not just battling opinions

Theoretica Applied Physics

Bringing 3D audio from the laboratory to the real world.

www.theoretica.us

 

[Newman]

“I’ve preferred less room sound prior to BACCH” and “a point of legitimate disagreement” and “I was very impressed”. Real science .

 

[Justdafactsmaam]

“I’ve preferred less room sound prior to BACCH” and “a point of legitimate disagreement” and “I was very impressed”. Real science LOL.

Yeah, real science. Unless you think JJ is a fake scientist I think it’s fair to say his opinions on room sound are science based.

As for my preferences they are no more or less valid than yours or anyone else’s.

 

[Duke]

This is a subject worthy of its own thread. I don’t think this conclusion is as solid as is commonly believed on this forum

Neither do I. My preference is for patterns which avoid the first ipsilateral reflections, a preference which is not supported by the Harman listening test data to the best of my knowledge. On the other hand "What speakers are preferred under these conditions?" is arguably a different question than "What do we want to do, and what's the best way to do it?"

Absolutely. But when it is broadband it does the trick. I’m rebuilding my dedicated room as we speak. The absorption is extremely broadband.

Good for you, doing it right and using true broadband diffusion!

Dead rooms have lower noise floors. Low level signals are more easily heard as signal.

Agreed. Not a fan of overly dead rooms, but then I haven't tried the BACCH system.

I’ve preferred less room sound prior to using the BACCH. I think it’s a point of debate. There are serious experts on both sides of this fence. JJ advocates the idea that the best room is no room as well as Ethan Winer.

And I respect your pre-BACCH preference as well.

I don’t want this to decay into an expert pissing contest with the usual ASR suspects. But I think it’s fair to say it’s a point of legitimate disagreement

I don't think you and I are in danger of descending into a pissing contest, and yes there are legitimate points on both sides. Some of it may go back to desired sweet spot width.

The Sanders 10Es. That is what I have. It is also what Edgar uses as a reference. They are very narrow dispersion from 150 hz up. One of the knocks on them have been the “head vice” narrow sweet spot. With the BACCH head tracking the “head vice” effect is completely eliminated. Eliminated in ways that can’t be achieved without the head tracking with two channel stereo no
Matter how wide the dispersion of the speakers.

Superb speakers imo, and the head tracking sounds like a very worthwhile upgrade. I use time-intensity trading, with speakers designed for it.

This is just battling opinions. No data?

Justdafactsmaam and I are having a conversation, not a battle. We are not disputing one another's experiences and conclusions.

 

[misterdog]

This is supposed to be a science based audio forum. What are the alleged objective problems with the JansZen speakers and where is the objective data to support them?

So here is the measured data from the Quad 989.

Quad ESL-989 electrostatic loudspeaker Measurements

Sidebar 3: Measurements Although the different kind of interaction between a panel speaker and the room can make it sound louder than its measured sensitivity would suggest, the Quad ESL-989 is still on the low side, at an estimated 83dB(B)/2.83V/m. Given its strict 100W power handling, this...

www.stereophile.com

All I can say is that the reasons for this speaker's undoubtedly superb sound quality are not readily apparent from its measurements. I hope to explore this subject in more depth in a follow-up.—John Atkinson

When you can present any data from the Jantzen's, other than

These may be the answer

Or

As for my preferences they are no more or less valid than yours or anyone else’s.

No. But I have heard them a few times. I was very impressed

Then maybe an objective discussion may be had.

Until then you just sound like a marketing sock puppet for Jantzsen.

I look forward to your measured data.



Just the measured data or facts please maaaaan.