Electrostatic speakers?

[dlaloum]

" The listeners who demonstrably differ from the easily identifiable population trends are those with hearing loss. "
- Hard to hear (translated from French : "c'est dur à entendre...").

BTW, anyone listened to the Quad ESL-X ?

I am outside the Harman 60-65%% preference (part of the remaining 35 to 40% of listeners), and I am a long term owner of various Quad ESL's (ESL57, ESL63, ESL989)

I have not heard the latest Quad's however....

 

[dlaloum]

The problem with MartinLogan ESLs is two-fold: 1st, they are hybrids and that in itself causes problems, and, 2nd, they are dipoles and cannot escape that curse, either.

The early Monoliths were phenomenal in some ways; but their bass simply could not keep up with their midrange and treble. ML has gone through many iterations in an attempt to mitigate this problem, including incorporating DSP in their speakers. Given their price and how well they sell, at least some listeners are happy with the result.

The dipole problem is a different story all together. And, I think ML's curvilinear design both solves it and makes it worse. You need the right room, specific placement of the speakers and the ability to rearrange furniture and alter the walls to make it work.

In my own situation, I covered the entire front wall that includes two floor-to-ceiling windows and a half-glazed patio door with heavy linen curtains. The rear wall includes a large gap into another room. And I papered the 2/3rds of the rear wall that is there with cork. The monoliths are at quarter points along the front wall just shy of 3 feet out and towed in about 15 degrees. The room itself is a living room with a variety of mismatched furniture and things on the walls that serve to diffract sound. Not many spouses would be happy with two enormous black monoliths dominating their living rooms, but, sonically, it works.

I always liked the CLS' (Martin Logan's full range ESL only reference speakers)- and found the Monoliths disappointing due to the disconnect between bass and esl - but I have not listened to their later efforts

 

[dlaloum]

I am new to speakers in general and would like to ask a pretty broad question on whether Electrostatic speakers are worth bothering with over conventional dynamic ones.

I have a lot of experience with headphones. There, electrostatic and planar drivers generally reign supreme over dynamics due to their rock bottom distortion that applies to the entirety of frequency response, including the low end. So even tho they very rarely have a natural bass shelf, you can easily add one with EQ and face no drawbacks because the drivers can take it no problem.

So I wonder if the same rules apply to electrostatic speakers. I looked through ASR and some other sources and couldn't find measurements that would give me a clear answer on this topic.
Looking at conventional speakers however, I have seen that they behave much more eratically than headphones. Many having distortion levels shooting through the roof in many places and pretty much always a sharp bass roll off. With only very few (usually also very expensive) speakers managing to avoid those problems.

Will electrostatic speakers help me combat those issues? Do they share the same technical advantages that electrostatic headphones have over dynamic headphones?

Yes at the driver/speaker level - the radiation pattern of large panels including their dipole/bipole behaviour - leads to very different positioning and room requirements when compared to "normal" speakers.

Many people approach ESL's with a bunch of unconscious assumptions about how speakers should be positioned, and the room optimised - frequently leading to disappointment.

You have to start by dumping all of your standard "drivers in a box" assumptions, and start with a clean slate in positioning the speakers and optimising the room.

If you do that - ESL's can often provide magic especially in the midrange, which other speaker designs struggle to achieve - like every speaker they have their own compromises, and like any speaker, you have to determine whether you are happy to live with those compromises.

Typically ESL's are more SPL limited than standard speakers, but they also tend to be much cleaner / lower distortion.
Bass output is another limiting factor - depending on the design, they may not LACK bass, so much as the bass frequencies are limited in SPL and at a lower level than the midrange.

Some of the bass limitations can be overcome now that we are in a DSP dominant world, where well tuned DSP and Room EQ can be used to match subs to ESL's in a way that was difficult or well nigh impossible prior to this millenium.

Living with ESL's requires a room where you can give them "space to breathe" - large rooms allow you to give the dipole design the room it needs to properly tune the direct to reflected sound timing & spl balance. (I was forced to retire my ESL's and revert to a marginally more "normal" design for lifestyle/room & WAF reasons)

If you are outside the market dominant 60 to 65% that prefer the "Harman curve" with boosted bass.... then you are much much more likely to be happy with ESL's

 

[dlaloum]

I'm biased. However, I'll try to give you an idea of what to expect. Most electrostatic speakers are dipoles whereas most dynamic speakers are not. They require a different mindset as to room placement and treatment. Is it worth the effort and expense? In my opinion, yes.
But there are classes of speakers that are also very similar to electrostatic, including ribbon, planar (similar to the headphones) and something called air motion transformers (AMT). All have their place and all can be part of exceptional speaker systems.
Two of the most famous names among electrostatic are Quad and MartinLogan. Both make exceptionally fine products, unfortunately, at exceptionally high prices, too. And because electrostatics are essentially giant capacitors, they can represent a brutal load on amplifiers. For example, my Monolith ESL panels are rated at a nominal 4 ohms; however, as frequencies reach ever higher that drops precipitously to 0.8 ohms at 20KHz and 0.6 ohms at 24KHz. Some amps simply implode, sometimes taking the panels with them. Luckily that is less true today.
Another problem is their sheer size. My panels are 26" wide and 48" tall on top of the enclosure that houses the dynamic woofer. The transition between the panel and it's dynamic partner depends on several factors, but the main one is simply square feet of surface. Mine crossover naturally at 6dB per octave at 125Hz so the woofer must take up the bass slack.
Therein is another problem. ESLs are really, really fast and large dynamic drivers just are not. When the Monolith was introduced, people loved its mids and highs but described its low end as muddy. I've resolved that issue with my monoliths by replacing the original woofers with what are probably the fastest model currently made. ML has also incorporated DSP in most of their top models.
A well designed dynamic speaker can have near vanishing levels of distortion until it is overdriven. It also can generally be driven at higher volume levels than most electrostatics. I haven't found that to be much of a problem. I can easily get neighbor complaint levels of sound from mine.
I really can't tell you that ESLs are for you. For me, I knew that I'd eventually have a pair after I first heard a pair of Dayton Wright XG8 models well over 50 years ago. Are they perfect? No. No speaker is. But I like the way they sound.

A side note - both ML and Quad have been making ESL's for a LONG time - you can often purchase 30 year old (or older!) ESL's from these brands at very reasonable prices - they may require some servicing - but typically the end result is a much lower price than new...
And although their later efforts have improved on some things - in many ways some of the earlier designs are just as good as the current models.
Find out whether you have a local engineer capable of servicing the speakers... and if you do, then hunt around for a vintage pair.

 

[dlaloum]

I agree that the vertical dispersion pattern of large ESLs is an advantage (as it is with other large planar designs). However, I disagree that ESLs inherently lack dynamics and punch.
Back to the DW XG8 (and its successor, the XG10) - Mike Wright placed the stators inside an inert gas (sulfur hexafluoride) balloon in order to increase the stator gap and increase the driving charges on the panels without arcing. He had set them up in a home in Cary NC driven with a pair of Phase Linear 700 amps in mono mode. Those speakers had dynamics and punch equal to or better than any dynamic drivers I've ever heard.
I suspect the increased stator distance is one of the factors in dynamics and punch, but I think there is another: the amplifier driving the ESLs. Many amps simply cannot handle the capacitance load.
I'm using an amp design that doesn't get a lot of respect in some quarters but with ESLs, it excels. I'm driving each ESL panel with a Mcintosh MC-2255 in mono/parallel mode. This doubles the current and halves the impedance of the circuit. I have the Monolith panels connected to the 1 ohm tap. They drink the power and the amp behind Mac's big autoformers could care less about impedance drops at any frequency.
There may be other solutions or explanations, however this is working for me.

Many people say "dynamics"/"punch" when they actually mean bass SPL's

In fact in many (most?) cases the dynamics of ESL's are almost always superior - a side effect of an effectively weightless driver - but their SPL is oft limited by the limited available excursion - mostly an issue in the bass, not the midrange or highs.

 

[dlaloum]

I think the only good way to use an electrostatic driver is the horn loaded pressure speaker. As a student of professor Josef Merhaut in the seventies, I would dare to post this link:

US3590169A - Electrostatic horn loudspeaker - Google Patents

An electrostatic pressure loudspeaker with a diaphragm vibrating at the rhythm of a signal frequency actuated by electrostatic forces operating between the diaphragm and at least one back electrode. At least one side of the diaphragm is connected with a horn through the input cross section of...

patents.google.com

But then you lose the benefits (and difficulties) of a panel speaker...

 

[dlaloum]

Question: for an ESL (or any dipole, really) ... most people try to space them away from the wall to delay the front wall reflection as long as possible. If you are unable to do this, should the front wall be treated with absorption? Or should we forget about dipoles if we are unable to space them away from the front wall? Even if we are able to achieve proper spacing, should the front wall still be treated with absorption?

If the speakers are angled, then the reflected front wall sound may need to travel from speaker, to wall, to side wall before reaching the listeners ears - a simple form of dispersion if you like. - placing them flat against the wall is a worst case... then you need about 2m or more between speaker and wall.
With angled speakers, and some curtains, I've had good results even at circa 1m from the wall.

 

[STC]

The key that you overlooked is that the vast majority of listeners prefer neutrality (in blind tests), not simply able to detect it.
View attachment 550317

Yes. But they are were a single speaker comparisons. With stereo in room it makes no sense like why some prefer vinyl over the most accurate digital.

ST

 

[RetroStereo]

I always liked the CLS' (Martin Logan's full range ESL only reference speakers)- and found the Monoliths disappointing due to the disconnect between bass and esl - but I have not listened to their later efforts

I agree with you. I loved the CLS in its several incarnations also. However all ML ESLs have always been way out of my price range. And interaction between ESL panels and dynamic driver woofers across all brands has always been problematic.
I bought my Monolith IIIs for $1100 second hand at the beginning of the pandemic (without either of their crossovers), a Dahlquist DQ-LP1 (the active low pass filter for the DQ-10 / DQ-1W speakers) and a pair of Apt model 1 power amps. I've been upgrading ever since.
The original woofers were acoustic suspension (I think most/all ML current hybrids use bass reflex) and a poor match for the speed of the panels. I've replaced them with Acoustic Elegance SBP12-4 Apollo woofers, reputedly, the fastest non-servo dynamic woofer available. I've custom tuned the DQ-LP1 for 50K ohm impedance power amps and a HF roll-off at 125Hz to match my panels. I've replaced the Apt amps with a trio of Mcintosh MC-2255 amps (1 for the woofers & 1 each in mono/parallel mode for the panels - the autoformers are a perfect solution for HF capacitance impedance drop to sub-1-ohm levels). And I'm replacing the panels & HV power supplies with new ones from ML.
No speaker is perfect; but, to my ear, these are darned close.

 

[Floyd Toole]

The interesting question is not whether listeners can detect deviations from neutrality. It is whether neutrality is actually the thing that makes the music feel alive.

A valid question. If wonderfully "alive" music is performed and captured or created in a recording control room, it would be good if someone else got to hear it as created. Unless there are some standards for sound reproduction where the music is created and where it is reproduced this can only happen by chance. Here is a slide from the show linked to earlier: https://www.audiosciencereview.com/...is-coming-discount.63666/page-13#post-2579817

 

[Floyd Toole]

If you are outside the market dominant 60 to 65% that prefer the "Harman curve" with boosted bass.... then you are much much more likely to be happy with ESL's

Interesting. I am the person who started the loudspeaker "Harman curve" thing but I don't understand your comment There is another Harman curve for headphones that Sean Olive originated and that one has some legitimacy).

First, all room curves, including the so-called Harman curve are results not targets. The original curve was what was measured in a room for a number of highly rated forward firing cone/dome/horn loudspeakers. That is all. It is explained in Section 12.3.5 in the 4th edition (originating in Section 12.2 in the 3rd edition). People jumped to the conclusion that equalizing any loudspeaker to match that room curve would result in "highly rated" sound - that is simply wrong! Room curves are dominated by far off-axis (reflected) sounds and the on-axis, direct, sound is a more important factor in the sound quality we perceive.

There is nothing uniquely good or bad about ESLs - like all designs they come in many "flavors". The dipole radiation characteristic is a distinguishing characteristic and it delivers a very different sound field from the common forward-firing designs. As you correctly point out, bass output is often a limitation, but good ones have enough bass to be very gratifying.

The amount of bass one "prefers" has to depend on what recording one is listening to. I find myself occasionally adjusting the bass level to compensate for recordings with too much or too little. Many listeners may have experienced bass deprivation in their youth and enjoy a little boost if it is available

Bass is disproportionately important to one's overalll impression of sound quality (about 30%), and the listening room dominates the quality of bass we hear so generalizations are risky.

 

[Chris A]

A valid question. If wonderfully "alive" music is performed and captured or created in a recording control room, it would be good if someone else got to hear it as created. Unless there are some standards for sound reproduction where the music is created and where it is reproduced this can only happen by chance. Here is a slide from the show linked to earlier: https://www.audiosciencereview.com/...is-coming-discount.63666/page-13#post-2579817

As an engineer by training and profession (now retired), I've always found it difficult to understand why someone would wish to bake into their home sound reproduction something known to be "wrong" with the loudspeakers--in order to make the overall presentation sound "better". In every instance where I have personally heard better/more neutral loudspeaker reproduction with very high quality recordings, I have always been the most impressed by what I've heard in those instances over loudspeakers having flawed performance in order to meet some customer segments' demands.

I think the root cause of some saying that they don't want the most neutral sounding loudspeakers can be traced to a few causes, none of which are valid for reproducing the best recordings:

1. Sometimes the loudspeakers being professed as "neutral" were actually not very good performers from the standpoint of phase distortion and modulation distortion. So best recordings that captured good venue acoustics that give the listener a sense of space and immediacy--were distorted by phase issues (particularly at lower frequencies) to sound bass shy, and sound "loud" to those that from time to time wish to turn the volume control up to something more approximating actual performance levels (i.e., modulation distortion).
   
   
2. Loudspeakers having poor dynamic range capability (i.e., much lower efficiency) are incapable of producing realistic music transients (like from cymbals, etc.), and sounded like they added an additional layer of recording compression, thus putting more distance between the listeners and the recordings themselves. Many people want to hear their favorite recordings as "better than the actual recording"--which of course is a mistaken notion that has no real basis in reality or fact.
   
   
3. The generally poor state of practice of popular music mastering practices make the entire experience of listening to sound reproduction systems at home a "derived experience", that actually relies on the listeners to accept something from their listening experience that doesn't correspond to actual acoustic performance of music. Most people that grew up before the age of multichannel compressors used in mastering (and mixing) today had to live with the near universal employment of bass attenuation in order to make the recordings sound louder. Nowadays, that deep bass-shyness found in recordings is put there by mastering practices that cater to the general deep bass-shyness of generations of stereo enthusiasts from past that have gotten used to this artificial sound through decades of this practice by mastering people. The general acceptance of "cheap small loudspeakers" also reinforces this issue.

There are of course more sources of why someone might state that they don't want the best performing, most neutral loudspeakers available in their setups, but I thought I would at least try to voice some typical reasons that I've run into that might explain this odd phenomenon.

Chris

 

[STC]

If wonderfully "alive" music is performed and captured or created in a recording control room, it would be good if someone else got to hear it as created.

I've always found it difficult to understand why someone would wish to bake into their home sound reproduction something known to be "wrong" with the loudspeakers--in order to make the overall presentation sound "better".

Thank you again, Dr. Toole.

We agree that the room strongly shapes what we ultimately hear. My remaining question concerns the two-speaker case specifically.

A single neutral loudspeaker can deliver a flat, smooth direct sound. However, once we use two neutral loudspeakers (stereo or even dual-mono), the combined sound field at the listener’s ears is no longer flat. The summation of the two direct sounds, their early reflections, and the room response produces a different total curve.

This raises a practical question:
If two perfectly neutral speakers cannot deliver a flat response at the listening position, is it possible that loudspeakers with a carefully chosen non-flat (slightly “coloured”) anechoic response could, after the two-speaker + room summation, actually produce a closer-to-flat result at the ears?

In other words, once we leave the single-speaker mono test and enter real stereo listening, does the ideal target for each individual loudspeaker remain strict neutrality, or does the acoustic summation suggest a different starting curve?

I’m not arguing for random colouration — only asking whether the mono preference for flat speakers still represents the optimum once two speakers are interacting in a room. Otherwise , I still don’t understand why someone who after auditioning a perfectly close to neutral speaker still opt for one that deviates from the flat response.

ST

 

[Chris A]

This raises a practical question:
If two perfectly neutral speakers cannot deliver a flat response at the listening position, is it possible that loudspeakers with a carefully chosen non-flat (slightly “coloured”) anechoic response could, after the two-speaker + room summation, actually produce a closer-to-flat result at the ears?

This is a legitimate function of mastering--to account for interaural perception events at the eardrums--not from baking in "exceptions" into the loudspeakers. All mastering (and mixing) guys that I've seen used loudspeakers (stereo or multichannel) to mix and master the various recorded channels. That's not something that the loudspeakers need to deal with.

I have to say that this is yet another example of the confusion that exists in sound reproduction circles because there are no standards by which the "professionals" must adhere to.

Chris

 

[Chris A]

I remember the Polk "SDA monitors" from the late 1970s-early 1980s that gave the listener a sense of 180 degrees of soundstage illusion--as long as you were sitting really close to the centerline between the loudspeakers, the space between the listeners and the loudspeakers were completely free of early reflections, and a pristine condition existed for side wall and front wall early reflections. Bob Carver did the same thing in his bigger preamp by introducing his "Sonic Holography", but not at the loudspeakers, rather via cross-channel mixing electronically upstream of the amplifier(s).

What happened to the SDA monitor and the Carver Sonic Holography products? Why did they stop making them?

Chris

 

[Floyd Toole]

A single neutral loudspeaker can deliver a flat, smooth direct sound. However, once we use two neutral loudspeakers (stereo or even dual-mono), the combined sound field at the listener’s ears is no longer flat. The summation of the two direct sounds, their early reflections, and the room response produces a different total curve.

This raises a practical question:
If two perfectly neutral speakers cannot deliver a flat response at the listening position, is it possible that loudspeakers with a carefully chosen non-flat (slightly “coloured”) anechoic response could, after the two-speaker + room summation, actually produce a closer-to-flat result at the ears?

In other words, once we leave the single-speaker mono test and enter real stereo listening, does the ideal target for each individual loudspeaker remain strict neutrality, or does the acoustic summation suggest a different starting curve?

It seems that you have not read my book, especially the 4th edition, where this topic is elaborately explained. The stereo soundstage consists of two essentially monophonic sources, the L & R loudspeakers for hard-panned images. The centre image is double mono, equal sounds from L & R and there definitely is interaural crosstalk, acoustical interference at each ear, resulting in an octave wide dip around 2 kHz - nothing else that really matters. This is the featured artist. All other images across the soundstage are positioned mainly by inter channel amplitude differences - amplitude panning using pan pots or coincident stereo mikes. Spaced stereo mics are also used, in which case there is a time difference as well. In any event, as the interchannel amplitude differences are increased the images are displaced from center, and the acoustical interference is gradually reduced, until it disappears at the L & R locations.

As Chris A said in his post, taking these effects into account is the job of the recording and mastering engineers. Stereo is not "real" so artistic judgement is required. A real challenge is in multichannel recordings where there is a real centre channel, and it does not sound the same as a phantom centre image. In movies the centre channel delivers most of the important sound - essentially all vocals and most on-screen sounds - but music presents a challenge, which is why many multichannel music recordings ignore the centre channel, or compromise by sending the signal to all three front channels.

None of this detracts from the need to start with technically accurate loudspeakers. When tests were done using loudspeakers with different levels of imperfection the differences were heard in mono, stereo and multichannel, and the technically accurate loudspeaker won in all playback formats - it is in the slide show. Mono is used in the multiple-loudspeaker comparison tests because the most common problem in loudspeakers, resonances, is most easily heard in that format.

 

[Floyd Toole]

I remember the Polk "SDA monitors" from the late 1970s-early 1980s that gave the listener a sense of 180 degrees of soundstage illusion--as long as you were sitting really close to the centerline between the loudspeakers, the space between the listeners and the loudspeakers were completely free of early reflections, and a pristine condition existed for side wall and front wall early reflections. Bob Carver did the same thing in his bigger preamp by introducing his "Sonic Holography", but not at the loudspeakers, rather via cross-channel mixing electronically upstream of the amplifier(s).

What happened to the SDA monitor and the Carver Sonic Holography products? Why did they stop making them?

Chris

Section 3.3 in the 4th edition discusses this topic. It is now possible to do a much better job than these solutions - inexpensive and powerful DSP allowing better crosstalk cancellation and the additional ability to create phantom images where the +/- 30 deg speakers should be, or even multichannel. There are discussion threads on this in this forum. Try a search on BAACH, a current implementation.

 

[Chris A]

Thanks...I'll read. I've digested both of your other versions (eds. 1/2 & 3) pretty thoroughly. I haven't had a chance to extract all the new info out of the 4th.

 

[MattHooper]

The king-penguin studies illustrate the same distinction. Chicks can locate and recognise their own parent’s call when it is played from a single loudspeaker in the middle of a screaming colony of thousands (Aubin & Jouventin). The loudspeaker used was a limited-bandwidth pro unit (Audax speaker) — hardly accurate by any hi-fi standard. What the chicks locked onto was not a complete, tonally accurate spectrogram. They used a small set of robust cues: the shape of the frequency modulation within a syllable, the beat pattern from the two-voice system, and the timing and structure of the call. Even when the signal was heavily masked and spectrally incomplete, the call remained real to them.

We see the same thing with 1960s land-line telephones. The channel was narrow, coloured, and full of artefacts, yet almost everyone could still tell whether it was their mother, their sister, or a stranger. The voice stayed real because the pauses, the rhythm, the speaking style, and a few surviving formant cues were intact. Tonal accuracy was missing; identity and presence were not.

Interesting post and to me it reminds me of some points I have made using some similar reasoning in terms of the type of characteristics, we can identify across a wide variety of sound systems of varying inequality.

My point however, is not to argue against the best science we have (from Toole et al).
The science shows convergence on preferences for uncoloured loudspeakers.

Rather, I make the point about my own attitude towards “ the artists intent.”

I have no argument against anybody wanting to close the circle of confusion - the ideal of using similarly uncoloured speakers/systems for production of music and playback in the consumer home. And the justification can be that this is getting closer to “ what the music production team heard and therefore closer to hearing the work as the artist intended.”
Totally fine.

The reason I don’t worry about the artists intent is along the lines of the type of examples you have given: I think it’s plenty easy to recognize the vision/intent of artists across a wide array of playback systems from very coloured to neutral.

Taylor Swift music sounds like Taylor Swift music whether you’re listening on earbuds, a kitchen, smart speaker, your laptop, smart phone, or any variety of loudspeakers.
By far the most salient artistic choices in melody rhythm, songwriting performance and many music production choices, translate across a wide range of playback. Everybody recognized the relevance of what the Beatles were doing including albums, like Sergeant Pepper, whether they were listening on transit radios car stereos, bedroom turntable systems, or Quad ESL’s or whatever.

So it’s like your example of the penguins recognizing chirps over a coloured speaker or the way we could easily recognize voices through Lofi phone systems of old. The artistic qualities of musicians and recordings tend to be recognizable, even on Lofi coloured systems. (I think of the example being a Rush fan, of the incredibly recognizable opening from their piece Cygnus X-1. I listened to that on so many different loud systems growing up… my dad’s big KEF 105.2s, my bedroom system, various systems at my friends houses, different car stereos, on walkmans… you name it. That particular sound of Geddy’s Rickenbacker bass emerging out of that particular distant alcove of reverb, was always instantly recognizable!).

So I don’t worry about chasing the artists intent. I will get enough of that pretty much no matter whatever system I use IMO.

Instead my aim is to choose a sound system that will please me, that will make as much of my music collection sound is enjoyable to me as possible.

The research presented by Dr Toole and others is therefore more interesting to me on the grounds that it investigated PREFERENCES for good sound. Not accuracy per se.

But it turned out that accurate speakers, in the sense of low colouration, tended to sound better to most people.

That aligns with my own tastes. I find myself being drawn to speakers that do not depart very far from accurate. I don’t like to hear very obvious peaks or dips in a frequency response, preferring smooth, even sound. (there are caveats to this, but that is the general trend)

So I am somewhat drawn to accurate speakers not because they are “ accurate” per se, but more because accuracy tend to be associated with low colouration, and low colouration generally sounds good to me.

 

[MattHooper]

As an engineer by training and profession (now retired), I've always found it difficult to understand why someone would wish to bake into their home sound reproduction something known to be "wrong" with the loudspeakers--in order to make the overall presentation sound "better".

Totally understandable.

As I mentioned in the previous post, I am generally drawn to speakers that sound smooth and even to my ear. I’ve owned very neutral speakers, and I’ve worked with plenty of well designed neutral speakers as well.

Nonetheless, I’ve had some very compelling listening experiences to certain speakers that were not totally neutral. I’ve mentioned this numerous times, but for instance during a large search for a new speakers a few years ago I included several auditions of Revel Performa speakers that I immediately recognized as smooth, even and very neutral.
Very obviously competently designed loudspeakers. But having played a wide variety of music that I’m familiar with through the Revels and then not long after that auditioned Devore O/96 loudspeakers… a wide baffle two-way design that certainly do not measure as pristine as the Revels, I found myself absolutely besotted by what I heard through the Devore speakers more than the Revels. There was a certain richness and heft to the presentation, and a particular bold bloomy-yet-still-rhythmic quality to the bass that really connected me to everything going on. And also seemed to give voices and instruments more of the density and scale, I perceive in the real thing. And recordings sounded very different from one as well.

I’ve had a few similar experiences from other speakers that were less than neutral. But as long as the particular colorations seem cannily integrated into the whole in a way that don’t shout “ coloured” to me, it seems I can really enjoy the experience.

One of the main reasons I did not buy the Devores is that, as much as I enjoyed them, I couldn’t get a home audition, and I was wary about the particular characteristics I heard.
The bass quality especially. Would I adapt to its particular bass character over time? Or is it something that would grow obnoxious and tiresome over time? I have occasionally lived with speakers in which I finally could not adapt to certain colourations, especially in the bass, and so did not keep them.

People have made similar critiques of adding colouration at the amplifier level - so for instance “ why would you ever introduce a consistent coloration from certain tube amplifiers?”

As a tube amp fan my answer is: because I really like that colouration!

Over and over I have compared my classic Conrad Johnson tube amplifiers to solid state amplifiers in my system, and every time I prefer the sound with the tube amplifiers, across virtually all music. (I was just recently going back back-and-forth again between my speakers being driven by my Denon AVR vs my tube amps… every time I like the tube amps significantly more).

I always had the caveat that it could be just a perceptual bias effect - I love the look of two amplifiers and glowing tubes (even though my amplifiers are in a separate room from my speakers). So when it be became possible to do a blind test between Conrad Johnson tube preamplifier and my Benchmark solid state preamplifier, I leaped at the chance. Turned out under level matched blind condition conditions…. yeah I identified the tube preamplifier easily and generally preferred it.

I’m using fairly neutral loudspeakers, so the level of colouration from the tube amps that I’m talking about is quite subtle.
So perhaps it’s more along the lines of “ different flavours of neutral” in the way some people may prefer the sound of slightly wider radiating neutral loudspeakers narrow radiating neutral loudspeakers. You’re starting with neutral, but just sort of nudging the sound in the direction you prefer.

1. Sometimes the loudspeakers being professed as "neutral" were actually not very good performers from the standpoint of phase distortion and modulation distortion.

I think this is a big one!

Is perhaps a slightly different take than the specific distortions you’re talking about . But it’s been my observation over the years that many audiophiles have assumed certain speakers to be neutral which were not in fact neutral. (Or were relatively flat on axis, but colorations came from off axis behaviour).

For instance: they use B&W speakers at Abbey Road don’t you know? They must be monitor neutral. And then when they hear that scooped out, exaggerated highs of modern B&W they think “ boy, accurate loudspeakers sure can sound overly detailed and ruthlessly, revealing… I guess what I want is more coloured “ musical” sounding speakers not accurate!”

Where of course most ASR members would recognize that well-designed accurate speakers these days tend to sound smooth and easy easy to listen to.

It reminds me of when a friend of mine was auditioning some slender PMC loudspeakers in his home and I came over for a few listens.
He found them somewhat “ ruthlessly revealing” and assumed that this was because they were accurate, because he knew that PMC also had a big business in pro monitors.

But I am immediately recognized they didn’t sound neutral to me. They sounded “cool”…lacking lower mid range/upper bass richness, with some rise in the highs. To me, they made virtually all recordings sound extra artificial, exaggerating, recorded artefacts.
I didn’t like them much at all.

I was able to find Stereophile’s measurements for those exact loudspeakers and sure enough, THIS is how they measured. (I note that Kal Rubinson, the reviewer, identified that character in his subjective impressions as well).

I think there are plenty of cases like this where audiophiles have assumed they were hearing the sound of accuracy, when it was anything but, and have drive misleading ideas about the sound of accurate speakers.