Listening in an Anechoic Chamber - a report

[EEE272]

Music only in that room - I'm indifferent to the whole HT thing, and get by with a 2.0 + 55" OLED system in a normal living room for TV.

I absolutely disagree with Toole on the issue, and would note he offers only an unsupported anecdote, that conveniently fits his predetermined enthusiasm for so-called envelopment via controlled reflections. (Worth noting: "the science" shows the majority of listeners choose clarity over envelopment [Lokki 2012] but if you're in the minority who prefer envelopment over clarity, then yes, Toole's your man, and certainly his work is extremely valuable, including to those majority members forced by circumstance to live in the minority's rooms.)

Music in an almost-anechoic room is characterized by extreme clarity - no blurring, smearing or masking by late-arriving reflections. For once, the old audiophile stuff about never-before-heard detail etc is absolutely evident, with, e.g., reverb tails clearly audible, trailing away to nothing. Stereo spread is correctly limited to the space between the speakers. Phantom images are sharp and precise. Depth (if recorded) can be dramatic. I really enjoy it.

My pursuit of this (admittedly eccentric) approach came from two directions - first, a private definition of accuracy, that says the sound waves at my ears should be prompted only by the bits in the incoming file, nothing else, with nothing taken away, and certainly nothing added. Privately it perplexes me that folks obsess over fidelity in the electronic realm, and then completely abandon fidelity in the acoustic realm, to the extent of deliberately adding delayed and amplitude-altered tones to those exiting their speakers. And then enthusing about it! It's the biggest disconnect I can think of. Suppose a DAC or an amp did that? What would ASR say about that?

The second direction was trying to clean up room modes, which led logically to suppressing LF reflection as completely as possible. Hence the super-deep absorbers.

The only identifiable negative is that removing room gain and reflections takes about 10dB out of the sound power in the room, which means using very much higher levels at the speakers to achieve the desired SPLs. In practice that generally means using speakers with high sensitivity, running pretty hard.

Thanks for the detailed description!
Really insightful! It was one of the points that Toole described that I could not believe.

One element I was still wondering about are phase effects, which you find on modern music. QSound might use this as well but I am not certain. Are these sounds also restricted to between the speakers? I would have expected that you are also surrounded by sound in this case. I sometimes have difficulties knowing if surround is on or off with such music.

 

[Inner Space]

One element I was still wondering about are phase effects, which you find on modern music. QSound might use this as well but I am not certain. Are these sounds also restricted to between the speakers?

Essentially Q Sound is a pre-applied comb filter effect, designed to "fight" the natural comb filter occurring between two speakers, so it works only on the direct sound, so it's fine in nearly-anechoic conditions - in fact usually better, because it isn't also fighting the reflections. Certainly the famous Roger Waters album delivers well. Phase effects are pristine, again because they're not polluted by random-phased reflections.

 

[Hipper]

Thanks for the detailed description!
Really insightful! It was one of the points that Toole described that I could not believe.

One element I was still wondering about are phase effects, which you find on modern music. QSound might use this as well but I am not certain. Are these sounds also restricted to between the speakers? I would have expected that you are also surrounded by sound in this case. I sometimes have difficulties knowing if surround is on or off with such music.

I can here the 'Waterloo Sunset' phase issue as described here:

https://forums.stevehoffman.tv/thre...-improve-your-stereo-playback-with-it.320990/

 

[dasdoing]

he offers only an unsupported anecdote, that conveniently fits his predetermined enthusiasm for so-called envelopment via controlled reflections

he seams to have a confirmation bias sometimes. He also seams to claim that LF ringing (long tails in the time domain) of modes are not audible after EQ (not sure this is true, but I have seen others saying he does).
The only explaination I have for this kind of bias is that most audiphiles don't seam to have a lot of rights in their own home lol (Even if they paid for it)

Privately it perplexes me that folks obsess over fidelity in the electronic realm, and then completely abandon fidelity in the acoustic realm, to the extent of deliberately adding delayed and amplitude-altered tones to those exiting their speakers. And then enthusing about it! It's the biggest disconnect I can think of. Suppose a DAC or an amp did that? What would ASR say about that?

It makes no sense at all. Edifier speakers over a Realtek DAC will sound better in a treated room than a Dutch and Dutch 8c with expensive DAC in a bare one (if you match the FR)

 

[abdo123]

It makes no sense at all. Edifier speakers over a Realtek DAC will sound better in a treated room than a Dutch and Dutch 8c with expensive DAC in a bare one (if you match the FR)

Not really, Low frequency extention is king. There is no need to visit extremes to prove a point.

 

[dasdoing]

Not really, Low frequency extention is king. There is no need to visit extremes to prove a point.

(if you match the FR)

 

[youngho]

I absolutely disagree with Toole on the issue, and would note he offers only an unsupported anecdote, that conveniently fits his predetermined enthusiasm for so-called envelopment via controlled reflections. (Worth noting: "the science" shows the majority of listeners choose clarity over envelopment [Lokki 2012] but if you're in the minority who prefer envelopment over clarity, then yes, Toole's your man, and certainly his work is extremely valuable, including to those majority members forced by circumstance to live in the minority's rooms.)

Re: Lokki, this was concert hall acoustics, and you got it backwards for the 2012 paper. The majority (=G2, 10/17 assessors) "prefer[red] louder and more reverberant sound with good envelopment and strong bass." The minority (=G1, 7/17) preferred " the halls with relatively intimate and proximate sound with good definition. In other words, in these halls it is quite easy to hear individual instruments and melody lines and the Reverberance is moderate." It was the 2016 paper that had contrasting results with majority (57%) preferring clarity over reverberance (43%), though this seemed to be somewhat dependent on the musical selection: "the overall preference results (Fig. 4) suggest that when the orchestra was playing louder (Bruckner) the overall preference is towards halls that have more clarity, but with more tranquil music (Beethoven) more reverberance is needed for preferred acoustics." The assessor group composition may possibly have varied. For example, I noted that the 2016 group included 10 professional musicians, who may be more sensitive to lateral reflections. No such description was given for the 2012 paper.

I was curious to know if you might be able to share any measurements of your room.

 

[Inner Space]

Re: Lokki, this was concert hall acoustics, and you got it backwards for the 2012 paper. The majority (=G2, 10/17 assessors) "prefer[red] louder and more reverberant sound with good envelopment and strong bass." The minority (=G1, 7/17) preferred " the halls with relatively intimate and proximate sound with good definition. In other words, in these halls it is quite easy to hear individual instruments and melody lines and the Reverberance is moderate." It was the 2016 paper that had contrasting results with majority (57%) preferring clarity over reverberance (43%), though this seemed to be somewhat dependent on the musical selection: "the overall preference results (Fig. 4) suggest that when the orchestra was playing louder (Bruckner) the overall preference is towards halls that have more clarity, but with more tranquil music (Beethoven) more reverberance is needed for preferred acoustics." The assessor group composition may possibly have varied. For example, I noted that the 2016 group included 10 professional musicians, who may be more sensitive to lateral reflections. No such description was given for the 2012 paper.

Yes, sorry, I mixed up 2012 and 2016. My bad. And yes, Lokki was working on concert hall acoustics, but I feel his work was really well conceived & executed, and is instructive in terms of listener preference generally. I suppose my underlying point was we have only a small handful of meaningful researchers available to us, sadly, and I find the unexamined assumption around here that only one of them should be followed to be poorly grounded.

 

[youngho]

Yes, sorry, I mixed up 2012 and 2016. My bad. And yes, Lokki was working on concert hall acoustics, but I feel his work was really well conceived & executed, and is instructive in terms of listener preference generally. I suppose my underlying point was we have only a small handful of meaningful researchers available to us, sadly, and I find the unexamined assumption around here that only one of them should be followed to be poorly grounded.

I didn't take away the same understanding in terms of making generalizations about listener preference except in terms of some clues as to how to apply those preferences to possible speaker choices and room acoustic conditions (I had tried to outline my amateur "thoughts" here: https://www.audiosciencereview.com/...-on-readings-of-lokki-bech-toole-et-al.27540/). The Bech/Lokki JASA 2019 paper was relevant to listening rooms, but given that they used expert listeners, it's not surprising that a drier acoustic environment was overall preferred and still in line with Toole's statements. Toole himself has addressed the matter of individual preference multiple times (linked above), even at the level of adjustable acoustics for different types of music, and the MLLL itself does not seem to be set up in a way to intrinsically favor lateral reflections, from what I can tell. I think it's hyperbole to use the word "forced" in your statement "those majority members forced by circumstance to live in the minority's rooms."

 

[dasdoing]

I doubt you can make a simple preference test with regular people.
If you are used to a wet environment a dry one will sound strange to you for a few hours at least. You would have to give participants a few hours of time to get used to it. at first you will just pay atention to what you are missing. only than you realize the actual ambience in the recording (that you normaly hardly hear)

 

[DanielT]

 

[Thomas_A]

My take of this is rather simple in terms of a ”normal average room”. Use carpets on the floor, fabric sofa/couches/pillows, paintings and decoration on the walls, coffee table.

Use extra damping at the loudspeaker wall side. No need to overwork treatment in the rest of the room, if you want to have an environment that is comfortable to spend time in. Too much damping around seating position is not comfortable to me. Damping at the speaker wall side does not negatively affect the listening area when having conversations etc but increases clarity when listening to music.

 

[Inner Space]

I think it's hyperbole to use the word "forced" in your statement "those majority members forced by circumstance to live in the minority's rooms."

I guess you could substitute "obliged" or "required" for "forced", but there are hundreds and hundreds of posts on this site basically saying, "I would like to do more room treatment, but can't because of WAF or whatever", so I don't really see it as hyperbole.

 

[dasdoing]

give wife her areas, and make clear that you will have your own, too. you don't have to give up deciding rights of the whole house to save your mariage lol.
it's a negotiation...like everything in marriage

 

[rdenney]

Some thoughts:

1.) I expect that most recordings are mixed with the assumption that they will be listened to in normal environments. I do have some recordings that I think have too much room effect, and those probably benefit from the driest listening environment--even outdoors. But I have recordings that are relatively dry, and clearly were mixed that with with the expectation of indoor listening. But I think this is overblown. No performance space for music is as small as my listening room, so whatever reverberation there was in the recording will still be different than any such in my listening space, and the recorded room will still come through clearly.

2.) Toole's argument, as I read it, is not that wet or dry is preferred, but that humans are highly adaptable to such and will hear through the room with clarity, just as they do with live performance. His argument fits with my experience.

3.) Musicians I know prefer to perform in reverberant spaces, but to listen in dry spaces. This is probably for the same reason that painters will sometimes study another painter's work up close to understand the brush technique--it's a technical evaluation rather than an emotional one. Non-musicians I know prefer to listen in reverberant spaces. Entirely anecdotal, of course. I hang around amateur musicians like myself, and our preferences are in part driven by the desire to gain as much room "improvement" as possible. None of us like to perform outdoors. I suspect this applies to a lot of amateur recordings, too, even those done by people who (for some unknown reason) were paid to do so.

4.) When I listen to music, I'm often also reading, or looking out the window (in our rural area, it's like Wild Kingdom out there, and nearly always something to look at), or playing with the cat, or something. A space so narrowly defined just for listening would not get used very much by me.

Rick "suspecting the idea of the super-optimized listening room is easier to live with than the actual fact" Denney

 

[Inner Space]

Some thoughts:

1.) I expect that most recordings are mixed with the assumption that they will be listened to in normal environments. I do have some recordings that I think have too much room effect, and those probably benefit from the driest listening environment--even outdoors. But I have recordings that are relatively dry, and clearly were mixed that with with the expectation of indoor listening. But I think this is overblown. No performance space for music is as small as my listening room, so whatever reverberation there was in the recording will still be different than any such in my listening space, and the recorded room will still come through clearly.

2.) Toole's argument, as I read it, is not that wet or dry is preferred, but that humans are highly adaptable to such and will hear through the room with clarity, just as they do with live performance. His argument fits with my experience.

3.) Musicians I know prefer to perform in reverberant spaces, but to listen in dry spaces. This is probably for the same reason that painters will sometimes study another painter's work up close to understand the brush technique--it's a technical evaluation rather than an emotional one. Non-musicians I know prefer to listen in reverberant spaces. Entirely anecdotal, of course. I hang around amateur musicians like myself, and our preferences are in part driven by the desire to gain as much room "improvement" as possible. None of us like to perform outdoors. I suspect this applies to a lot of amateur recordings, too, even those done by people who (for some unknown reason) were paid to do so.

4.) When I listen to music, I'm often also reading, or looking out the window (in our rural area, it's like Wild Kingdom out there, and nearly always something to look at), or playing with the cat, or something. A space so narrowly defined just for listening would not get used very much by me.

Rick "suspecting the idea of the super-optimized listening room is easier to live with than the actual fact" Denney

Rick, I largely agree with you here, which is why I took pains to call my own preference a private obsession. I wouldn't necessarily expect anyone else to be as enamored, but on the other hand I wish people wouldn't dismiss the notion based simply on hearsay, rumor, anecdote, conventional wisdom, or lay intuition.

 

[youngho]

I guess you could substitute "obliged" or "required" for "forced", but there are hundreds and hundreds of posts on this site basically saying, "I would like to do more room treatment, but can't because of WAF or whatever", so I don't really see it as hyperbole.

It is an interesting viewpoint to consider, certainly not one I would usually adopt. Force usually implies something much stronger than obligation or requirement, typically involving a high level of threat or coercion extending all the way up to potentially include physical means. Otherwise, on an individual level, I am "forced to" breathe, blink, drink, urinate, eat, and defecate. On a personal level, I am "forced" to provide material necessities for my family and tend to emotional needs. Outside of the house, I am "forced" to wear clothes and refrain from seriously harming people, even if "I would like to do" otherwise. On a professional level, any job could be described as "forced" labor. I would never describe any of these things as being "forced," so I very much see it as hyperbole. (I was going to say something about being forced to follow some modicum of civility on ASR, but that does not seem to have applied in this thread). I find that people often tend to use loaded (negatively) terms when describing viewpoints with which they don't agree.

Rick, I largely agree with you here, which is why I took pains to call my own preference a private obsession. I wouldn't necessarily expect anyone else to be as enamored, but on the other hand I wish people wouldn't dismiss the notion based simply on hearsay, rumor, anecdote, conventional wisdom, or lay intuition.

What you have is basically an extension of control room design, though probably you should have a 1-2' layer of Basotect on the floor between the speakers and the listening position, since floor reflections can be an important source of coloration with effects on both timbre and spatial perception (Bech 1995, 1996, 1998). A rug is not adequate to address the lower frequencies involved.

I do wonder about the absorption of Basotect at non-random-incidence (BASF provides very limited measurements). Toole had provided interesting data from Peter D'Antonio in the first/second edition of Sound Reproduction regarding fiberglass along these lines. It would be interesting to see measurements from your room if you are willing to share any, especially the lower frequency decays.

 

[rdenney]

Rick, I largely agree with you here, which is why I took pains to call my own preference a private obsession. I wouldn't necessarily expect anyone else to be as enamored, but on the other hand I wish people wouldn't dismiss the notion based simply on hearsay, rumor, anecdote, conventional wisdom, or lay intuition.

I note that Russell said something similar: some people were disturbed by the effect of an anechoic chamber, but he found it to be peaceful.

As for me, I can't imagine a worse nightmare for trying to make music--hearing only bone conduction and direct sound from an instrument that has for 185 years been refined for application in reverberant spaces. But I own some recordings that might sound pretty good in an anechoic space.

Edit: Extended digression removed. I've already had one extended digression removed today.

Rick "much ado about nothing" Denney

 

[Inner Space]

It is an interesting viewpoint to consider, certainly not one I would usually adopt. Force usually implies something much stronger than obligation or requirement, typically involving a high level of threat or coercion extending all the way up to potentially include physical means. Otherwise, on an individual level, I am "forced to" breathe, blink, drink, urinate, eat, and defecate. On a personal level, I am "forced" to provide material necessities for my family and tend to emotional needs. Outside of the house, I am "forced" to wear clothes and refrain from seriously harming people, even if "I would like to do" otherwise. On a professional level, any job could be described as "forced" labor. I would never describe any of these things as being "forced," so I very much see it as hyperbole.

Sincere apologies, and nothing personal, but discussion of common vernacular expressions taken to this kind of level is making me lose the will to live. Over and out.

 

[Inner Space]

As for me, I can't imagine a worse nightmare for trying to make music--hearing only bone conduction and direct sound from an instrument that has for 185 years been refined for application in reverberant spaces. But I own some recordings that might sound pretty good in an anechoic space.

Surely we were discussing listening to recorded music, not making live music. Immense difference.