Electrostatic speakers?

[gnarly]

I'm not sure if you're just giving me more work to do, or have you actually been drinking the kool-aid coming out of these electrostatic speaker discussions? You haven’t spotted any issues?

I hope neither
I had read the new posts starting a few days ago, and mainly only saw discussions about radiation patterns...that didn't appear to have much if any myth content. I have no clue about the existence or not of segmented delay lines, so no comment there.
When it comes to electrostats radiation patterns, I have pretty strong ideas. I see them as operating as line arrays in both vertical and horizontal dimensions. I think Harry Olson's classic line array work describes them well under that viewpoint.

I was just looking for what you considered to be myth within what was recently discussed.
Must say, reading your full myth buster reply, I can't get on board with parts of it.

Quad concentric rings. Then there is the myth that the Quad's concentric delay lines meaning that they don't have a beaming problem. Sounds good in theory but in practice the smallest one is four inches in diameter. Now, if someone released a conventional speaker with a four inch tweeter, it would be universally derided, and for good reason, because it would beam like a laser on steroids. But on the Quad it solves beaming? Myth. Sure it helps, but that’s because the untreated stat panel is so bad.

Stat's vertical beaming is an asset imo. Operating as a line array with the tightest c2c spacing possible for VHF drivers, lets the same sound arrive at any vertical height up to the top of the panels. And limits energy heading to the ceiling for destructive reflected comb filtering.
Horizontal beaming...stat's Achilles heel. . A horizonatal line array simply calls for an extremely precise listening position, ime. (Yes, I've turned straight line arrays on their sides)
I've never heard Quads, and know nothing about the rings. I've heard plenty of flat, segmented, and curved panels which all require precise listening focus, some more than others.
I postulate that the vertical line array action (better way to describe than beaming, as beaming only occurs above the height of the panels),
and the same line array action in the horizontal plane that requires precise perpendicular orientation to the horizontal lien,
is what helps give stats their unique sound....along with no crossover, and being a full range membrane.

Square wave perfect. Then we got the hoary old story of Peter Walker showing a perfect square wave coming out of a Quad, and how amazing this means the speaker is. This is a myth and a con job on two levels. First level, that ain't no perfect square wave. Any high resolution examination of the leading edge and the top corners would show grievous irregularities. Sure, plenty of speakers would be far worse, especially in its day, but if someone set out today to specifically design a conventional speaker to play a good looking square wave, the Quad square wave might not 'win'. Second level, there is no need for a speaker to reproduce a square wave well. It's a false goal. Basically, showing off the square wave for a speaker is a showroom stunt. A myth.

Sorry, but imnsho this is just flat wrong. Square waves are an excellent test, better and more precise than Fourier analysis really.
A perfect impulse, an excellent flat mag and flat phase transfer function..... produce near perfect square waves...I say near perfect because I've found square waves to be more discerning than FFT
Anyone who disses the legitimacy of square waves, is basically just saying they don't place value on phase and/or time alignment.
The argument about high rez peering into the leading edge and corners is a copout imo...the lack of rez is simply due to the limited bandwidth of audio. Square waves must be evaluated compared to what approaches perfect within the audio bandwidth.

Dipole bass and sub. The idea that dipole speakers don’t integrate well with a conventional subwoofer and sound superior with a a dipole subwoofer eg a Ripole. The far more likely reason for one to prefer a subwoofer with diminished LF extension, like a Ripole, is because you are simply not doing a normal subwoofer correctly.

I think open-baffle subs that have more dipole like radiation, cardoiod like to the sides, may make a decent improvement matching stats that radiate front and rear. Dunno, but it makes some sense.

You know what really causes a subjective impression of slow bass? A strong, deep-reaching subwoofer without any room correction.

Gotta define room correction. If you mean acoustical, totally agree. If you mean DRC, disagree other than for knocking down modes with a few judicious PEQs.

Lighter than air.

Funny, and yep only a zealous dope would claim that.

BTW I sometimes wonder about being asked to type unnecessary repetition. I get it that myth makers are tireless fans, so are bound to not listen to the realities when stated and therefore just repeat the myths next time the topic comes up, but why don't the myth readers learn when the mythbusting facts are being expounded and stop drinking the kool-aid?

fwiw, you seem to sometimes kill both myths and facts together...which puts one leg into the subjective camp as surely as believing myths..
That said, I do appreciate your myth busting work

 

[MattHooper]

I have been testing (rather competent) dipole electrostats under true blind test conditions, comparing them with conventional ones.

Would say, a part of the myths have a base, others are just a myth.

The first time I heard Quad ESL 63s at my friends house it was a revelation. I didn’t know anything about electrostatic speakers but had never heard anything quite like it.
The sense of the speakers being utterly transparent windows, with zero sense whatsoever of a sound that I traditionally associated with “ box speakers” felt somewhat uncanny. Is clear that many people have had similar reactions. It wasn’t like I had never heard excellent sound from a dynamic speaker before - I grew up with an audiophile dad and several different speakers, but mostly settling on the KEF 105.2 speakers. Those things imaged like crazy. And yet there seems to be still a different sound to the Quads than I had encountered before.

Those are of course just informal impressions, and not some declaration that everything ever said about electrostatics was true.

However, my friend did have me do in informal blind test between Spendor BC1 speakers and the Quads. What was interesting was actually how surprisingly similar they sounded!

But ultimately it was that slight recognizable “box speaker” impression I had when the Spendors were playing, completely absent in the Quads, that allowed me to identify which was playing in the blind conditions.

 

[RayDunzl]

Sounds like we mean the same phenomenon

I think so, and provided what I think is an interesting comparison measurement.

 

[RayDunzl]

Don’t forget the general perception that stat panels have diaphragms that are so light that they have both incredible transient response due to the diaphragm not being ‘slowed down’ by its own inertia, and simultaneously supreme damping by the air being heavier than the diaphragm. Turns out that the diaphragm is several times heavier (not lighter) than the air, but even so, the impedance of the air does strongly dampen the diaphragm….at high frequencies. The net result is that the air load is present when it is not needed ie high frequencies whereby the diaphragm cannot respond instantly to transients in music because it is so over dampened, and not present when it is most needed, ie low frequencies where all the drum resonances of the diaphragm lie and also frame resonances. It is actually less responsive to transients than a good tweeter.

Well... Maybe...

Three transients, as impulses (one sample full scale), each 1 millisecond apart.

Top, source
Bottom, in-room recording

Contrived "transient":

Again, source, and in-room recording.

The wiggles 1 millisecond after the transient is reflection off the base of mic "desk" stand and the top of the sofa.

Looks like my panels tried pretty hard to Do The Right Thing.

 

[RayDunzl]

Square waves are an excellent test, better and more precise than Fourier analysis really.
A perfect impulse, an excellent flat mag and flat phase transfer function..... produce near perfect square waves...I say near perfect because I've found square waves to be more discerning than FFT

How is a speaker supposed to produce the flat area of a square?

The signal to make the speaker move has stopped rising, so the speaker becomes motionless.

What will maintain the "sound pressure" during the time the driver is stopped at the top and bottom of the wave?

--

I've seen mine produce a somewhat reasonable square for the microphone at some frequencies - if I sweep a square.

But most of the time it is off.

--

An area of a frequency swept square where the speaker manages to square things up, while it is much worse at the lower and higher frequencies around that happy spot, and maybe some others.

 

[Newman]

I am struggling to understand this statement. Of course sighted bias is real and people can imagine all sorts of things. However, are you saying that no one can listen to a set of speakers and determine they have a certain quality without a blind test?

I am only reflecting what the audio science has established. And it is pretty clear on this point. The answer to your question is, unfortunately for us, yes.

Fwiw, my first serious listen to Martin Logan ESLs was with a used pair of 15As in a large dealer room. I wasn't there to look at them, I just dropped in to visit this store while travelling for business. They were the cheapest speakers in the room and several pairs of much more expensive, more traditional speakers were also set up in front of me. I did not know which speakers were playing when I sat down, I had to ask the owner because there were a bunch of amps on the floor in front of the seats that I didn't want to step over, lol. Although my time there was brief, during the demo I felt the imaging was the best I've heard to date, but I am willing to admit it might have been the room and at the least I believe he set up the MLs with care. But I do not believe there was much sighted bias at play because I did not know much about ESLs at the time of listening so did not know any of the myths. And they were the least expensive speakers in the room. Am I missing a source of bias with that assessment?

There have been so many anecdotes that people bring up to 'test the margins' of the need for controlled listening evaluations, but the only way to know is to test each anecdote! Without such, the only safe conclusion is not to trust the anecdote. Because the sighted listening effects are counterintuitively strong and the human brain wants to trust them.

Of course this is horrible news for the audiophile who has built his knowledge base on sighted listening and shares it on forums far and wide as audio reality, therefore many of them enter denial. It becomes an Inconvenient Truth and the white-anting begins.

Cheers

 

[MattHooper]

I am struggling to understand this statement. Of course sighted bias is real and people can imagine all sorts of things. However, are you saying that no one can listen to a set of speakers and determine they have a certain quality without a blind test?

I am only reflecting what the audio science has established. And it is pretty clear on this point. The answer to your question is, unfortunately for us, yes.

Unfortunately, you will find Newman here conflating his own interpretations with
“ the science” which leads to these type of exaggerations. (There are countless examples disconfirming Newman’s sloppy claim. Among them: Erin of Erin’s Audio Corner listens to loudspeakers in sighted conditions before measuring them, and Erin regularly detects and describes characteristics - frequency response character for instance - that are validated by the measurements he does afterwards).

If you took Newman’s response seriously, virtually nothing on this website, including all the appeal to measurements, would be of use to any audio consumer. If you could only determine what a speaker sounds like via blind testing, then buying speakers for the actual conditions people use them - informal sighted listening - would be pointless.

There’s certainly much good to be said about the role of blind testing. It’s unfortunate though when some people use it as a sort of cudgel to whack-a-mole any sighted listening report they disapprove of.

Fortunately, most members here have nuanced views.

 

[Newman]

Unsmoothed room-corrected frequency response

MartinLogan reQuest vs JBL LSR 308

JBLs located next to the reQuests. The JBLs are my daily drivers.

The only explanation I have is sharp cancellations due to the wide dispersion JBLs working the walls and the floor and the ceiling and working the walls some more.

View attachment 462512

Toole explains why combing off room boundaries is not an issue, so trying to avoid it is a wrong approach.

 

[RayDunzl]

Toole explains why combing off room boundaries is not an issue, so trying to avoid it is a wrong approach.

I don't have to try to avoid it.

I got it without any extra effort.

 

[Newman]

I don't have to try to avoid it. I got it without any extra effort.

And massive compromises that actually are important.

 

[MattHooper]

I’m sure Ray finds his compromises to be “massive.”

Poor guy.

If only he just listen….

 

[RayDunzl]

I like natto too.

 

[dlaloum]

I have been testing (rather competent) dipole electrostats under true blind test conditions, comparing them with conventional ones.

Would say, a part of the myths have a base, others are just a myth. Would not say they sounded anyhow natural or realistic over overly precise in terms of localization/imaging. Rather the opposite, phantom sources appear unnaturally broadened and pulled vertically, depth-of-field is exaggerated. On the other hand, the imaging is pretty stable and offers reduced proximity, which some people like. I prescribe this to excellent attenuation of side-wall reflections, absence of band-limited localization instability (´jumping´ phantom sources) and good tonal balance of the rear wall reflections being responsible for quite some degree of diffuse field in the room while on the other hand the sheer size of the panel, the rear SPL maximum become audible.

Excellent midrange clarity I could also confirm, but would assume this is rather an absence of ´muddy´ lower midrange reverb thanks to balanced directivity than a unique quality of the speaker. Other concepts like cardioids, electrodynamic dipoles or line sources can achieve something similar.



That is not a myth. At least if you are dealing with a fair amount of room modes, increasing RT60 in the lower mids, and hybrid stats like Martin Logan with a higher x-over req. The versions with true dipole woofer (like the one @traind has mentioned) are superior which is particularly measurable between 100Hz and the x-over freq between dipole sub and stat panel.

Yes, ELS' have an advantage (difference?) over omni's in that their output to the sides is negligible, that means that they can be positioned close to side walls, without major concern for reflections from the side....

That can allow them to work well in somewhat narrower rooms.

 

[dlaloum]

The first time I heard Quad ESL 63s at my friends house it was a revelation. I didn’t know anything about electrostatic speakers but had never heard anything quite like it.
The sense of the speakers being utterly transparent windows, with zero sense whatsoever of a sound that I traditionally associated with “ box speakers” felt somewhat uncanny. Is clear that many people have had similar reactions. It wasn’t like I had never heard excellent sound from a dynamic speaker before - I grew up with an audiophile dad and several different speakers, but mostly settling on the KEF 105.2 speakers. Those things imaged like crazy. And yet there seems to be still a different sound to the Quads than I had encountered before.

Those are of course just informal impressions, and not some declaration that everything ever said about electrostatics was true.

However, my friend did have me do in informal blind test between Spendor BC1 speakers and the Quads. What was interesting was actually how surprisingly similar they sounded!

But ultimately it was that slight recognizable “box speaker” impression I had when the Spendors were playing, completely absent in the Quads, that allowed me to identify which was playing in the blind conditions.

Ditto here for the "box" impression....

there is something about most "box" speakers that sounds different.... and I prefer the sound of "non box" speakers.

This is NOT about electrostatic vs Dynamic - I replaced my ESL's with Gallo Nucleus Reference 3.2's - which I came across when shopping in a white goods store, that had for a brief time, tried to have an upmarket Audio/AV section.... I was not looking for them - but as I heard the sound, I thought, that is actually excellent and checked out what was playing..... this ultimately led to their replacing my ESL's and achieving an improved WAF as a result.

They are distinctive in that they do not have a box!! (and Anthony Gallo was very particular in designing for resonance control!)

Perhaps a large part of why some of us prefer stats, has to do with the resonances, and/or sound emissions from the side panels?

Yeah - our love for stats may to some degree be accounted for by parameters that can be achieved in other ways.... QED.

Having said that - the Gallo's do not quite achieve the midrange transparency that the stats did.... close but no cigar.

 

[MattHooper]

Ditto here for the "box" impression....

there is something about most "box" speakers that sounds different.... and I prefer the sound of "non box" speakers.

This is NOT about electrostatic vs Dynamic - I replaced my ESL's with Gallo Nucleus Reference 3.2's - which I came across when shopping in a white goods store, that had for a brief time, tried to have an upmarket Audio/AV section.... I was not looking for them - but as I heard the sound, I thought, that is actually excellent and checked out what was playing..... this ultimately led to their replacing my ESL's and achieving an improved WAF as a result.

They are distinctive in that they do not have a box!! (and Anthony Gallo was very particular in designing for resonance control!)

Perhaps a large part of why some of us prefer stats, has to do with the resonances, and/or sound emissions from the side panels?

View attachment 462597

Yeah - our love for stats may to some degree be accounted for by parameters that can be achieved in other ways.... QED.

Having said that - the Gallo's do not quite achieve the midrange transparency that the stats did.... close but no cigar.

A local audio store used to sell Gallo when that brand was more prominent, and I had lots of fun listening to the refs and some other models. I always luxuriated in their spacious imaging.

I had Waveform speakers for a while - the ones with the egg shaped mid/tweeter unit.
Those things disappeared and damaged like bastards.

I could say the same for my current loudspeaker.

And yet… until recently, a friend of mine owned electrostatics, and there’s just something seemingly different there. It’s like when I’m in front of a regular dynamic speaker that is imaging really well it’s hard to imagine things sounding more pure, but in front of a good electrostatic it’s like “oh yes, there are other levels of this, where the sense of a speaker truly disappears.”

 

[Newman]

Yes, ELS' have an advantage (difference?) over omni's in that their output to the sides is negligible, that means that they can be positioned close to side walls, without major concern for reflections from the side....

That can allow them to work well in somewhat narrower rooms.

By "work well" I hope you don't mean it's an audible advantage, because the science seems to say that the opposite is true for stereo.

 

[Arindal]

there is something about most "box" speakers that sounds different....

There are several possible explanations for this impression which a lot of people report, so I consider it to be more than just anecdotal.

- baffle step and directivity, i.e. the transition between omnidirectional and directional behavior

- audibility, if indirect, of phenomena like resonances happening inside the enclosure volume

Concepts using a conventional enclosure design but avoiding the directivity step in the typical frequency band, in my understanding tend more towards ´non-box-speakers´ in terms of sound character, may it be broadband constant directivity horns, hybrid horns with big midwoofers, line sources, infinite baffle speakers. Nevertheless concepts like dipoles and cardioids are closer to planars in my observation. If you have heard the midrange clarity of a Kii Audio, Ecouton or bigger MEG, there is little to be desired.

Perhaps a large part of why some of us prefer stats, has to do with the resonances, and/or sound emissions from the side panels?

I doubt that. As big planar speakers have inherently bad ratio of force per diaphragm area, control and diaphragm stiffness, they are almost certainly more prone to resonances with parts of the diaphragm acting out of phase with others. It is just happening in a different frequency range (higher) compared to resonance issues of conventional box speakers which are mostly limited to bass and (lower) midrange.

I suspect the baffle step/directivity issues to be dominant, although I have been taking part in experiments under anechoic conditions proving that volume resonance is audible as well at least in the lower midrange, contributing to the ´muddy´, dominant lower midrange which many people associate with box speakers.

By "work well" I hope you don't mean it's an audible advantage, because the science seems to say that the opposite is true for stereo.

Supressing early reflections and doing so in a frequency-independent manner, is always an audible advantage even if it comes at a price.

Which science are you referring to?

 

[Arindal]

Horizontal beaming...stat's Achilles heel. . A horizonatal line array simply calls for an extremely precise listening position, ime.

It is not only a matter of positioning and angling. Both vertically and horizontally narrow beaming caused by a planar diaphragm forming an even wavefront, also poses problems as it is pretty frequency-dependent. Depending on the size of the planar panel, you have frequency bands at higher frequencies which simply ´disappear´ from the reverb. The rear behavior of a dipole might compensate partly for that, but it is not the same.

From theoretical point, it would be advantageous to have a rather high but slim panel shape, so horizontal and vertical beaming effects happen in different frequency bands. Curved panels (Martin Logan) or additional narrow ribbon-shaped tweeters (Apogee, Magnepan) can be a solution to that just as other measures of directivity control (like magnetostats with waveguides as used in sound reinforcement).

The question is: how slim is slim? I would say, pretty slim. Something in the region of the wavelengths of highest octave we can hear, i.e. approx. 3cm in width, is ideal. Which arises another question, which driver technology can achieve such for almost fullrange operation? Maybe an AMT, which I personally prefer over planar stats because it can be much much smaller for the same performance, and employs pretty clever methods of suppressing breakup and resonances. Try to bend a rigid cardboard and you know what I mean.

I've never heard Quads, and know nothing about the rings.

The stators are segmented (up to 8 ways depending on the model, if I am not mistaken), with highest treble being handled solely by the central circular area, with more outer rings coming into play the lower you get in frequency. It is just an array of low-pass filters with the large fraction of the panel handling only bass and lower mids:

Given the year of its invention, it is really a sophisticated and elegant solution. It is not really solving the narrowing-the-beam issue but keeping it constant over various frequency bands at least.

Stat's vertical beaming is an asset imo.

I agree, as no-one needs dominant ceiling and floor reflections. The downside is that most of stats are too high in order to achieve vertical beaming and sufficient diaphragm area, which contributes to vertically blurred, rather vague localization.

Square waves are an excellent test, better and more precise than Fourier analysis really.
A perfect impulse, an excellent flat mag and flat phase transfer function..... produce near perfect square waves

From a theoretical standpoint, yes, but what is this good for in terms of reproduction quality? It is almost useless, if not misleading. The resulting graph is mostly a result of the reproduced frequency range plus phase shift or group delay issues between the sine frequencies contained in the squarewave.

Anyone who disses the legitimacy of square waves, is basically just saying they don't place value on phase and/or time alignment.

No, it is not about disputing phase issues as a whole, but about asking which alterations are audible and which not. A squarewave or single step response, are almost useless for this. Audible changes (like low frequency group delay distortion) are not visible, and visibly pretty disturbing alterations to the signals (such as a low-oder allpass or a simple crossover somewhere in the middle of a the spectrum) are not audible because the phase shift is below the thresholds.

How is a speaker supposed to produce the flat area of a square?

In theory: vast frequency range reaching very low and very high at the same time, plus low phase shift or almost no group delay distortion in the frequency bands where the sine frequencies became more dense.

What will maintain the "sound pressure" during the time the driver is stopped at the top and bottom of the wave?

The capability of the speaker to reproduce low frequencies equals its capacity to maintain constant air pressure over a certain duration. Diaphragm movement is not the same as sound pressure over time.

An area of a frequency swept square where the speaker manages to square things up, while it is much worse at the lower and higher frequencies around that happy spot, and maybe some others.

Signs of an allpass or minimum phase x-over filter causing a phase shift between several spikes in the spectrum, i.e. sine wave components of the square wave. In frequency bands with low phase shift or coincidentally n*360deg ones the waveform looks intact. Does not allow any conclusion on audibility or reproduction quality, though.

 

[dasdoing]

do you haver the link?

 

[dasdoing]

this is so crazy. a shame audiophiles love to show of their system.....else they wouldn't insist on wide dispersion and we would have better options of speakers that limit room interaction.