An Enticing Marketing Story, Theory Without Measurement?

[j_j]

The ERB/critical band is not the resolution of the hearing system as it relates to all things. It is better described as being related to the discrimination of tones and how multiple tonal components interact with each other, thereby entering the domain of timbre.

I'll have to disagree here. The cochlear filter shape (yes, it varies with level, etc) detected by inner hair cells and then compressed via outer hair cell is a basic input to the rest of the CNS. While you can catch features of the partial loudnesses that result, and the CNS does, the basic cochlear filter can not be eliminated from the system, it is fundamental to everything auditory, and is much more than simply related to the 'discrimination of tones'. In fact, it doesn't have that much relation to "discrimination of tones" and is better thought of as a way to describe the actual signal capture on toe cochlea. A proper ERB scale provides a scale for which masking is uniform across frequency, for tone or noise or anything else, where best time response is easily understood as the result of the cochlear filter impulse response reaching the point of detection, etc. Forget Critical Bands, Scharf did a good job with pencil and paper and mechanical calculators, but ERB's are much more useful, as they provide a testably much more uniform partitioning. There is much publication out there about this, from Jont Allen, Joe Hall, Dick Lyons, etc. In many places, ERB's are confused with time domain artifacts at low frequencies, but a quick understanding of transmission line filters can help you sort that.

It is MUCH more important than you make it out to be, and has not failed either in "room correction" (I use quotes because it's a system correction, correcting rooms with big problems is something we very much agree on is not going to happen), speech coding, music coding, spatial analysis, etc. In room correction, with understanding of the time-domain issues below 1kHz, it provides a simple framework that allows one to decide what to fix, and what to average.

Please don't discount this. It's much, much more fundamental than you make it out to be, and there's no way around it in the actual human.

 

[j_j]

Brian Moore, the author of ERBs, said to me: "The auditory filter bandwidths (ERBn values) are about 1/6 to 1/4 octave at medium to high frequencies. And . . . within band irregularities in response can have perceptual effects".

Why is why, again, I say that you should look at partial loudnesses (which is the compressed ERB output).

The 1/6 arises in my experience from ignoring time-domain variations in partial loudness. I'll agree with 1/4 octave, again, give or take, above 400 Hz.

 

[Duke]

The interaction between the DI of the speaker and the resonances of the room can be "interesting". Having the room have a peak where the power response of the speaker rises vigorously as a result of the DI changing can be "interesting". Not necessarily in a good way, mind you.

So are you talking about the rise in the speaker's power response at low frequencies as the speaker's directivity index approaches zero?

Ime there is a definite rising trend as we go down in frequency in many rooms, but in practice it's not a nice neat rise, as it is subject to the modal behavior of the room. Perhaps there are situations where "the room [has] a peak", but in my experience rooms have multiple peaks at low frequencies, and those peaks move to different frequencies as the position of listener or loudspeaker changes.

However, room modes/standing waves do change dramatically with location of the ears or mic. That is the problem to be addressed. Mode cancelling/attenuation using multiple subs greatly simplifies the situation, but only when the budget allows. Good news is that with multiple subs the total system efficiency rises, so they can be smaller subs.

I manufacture a four-piece multisub system called the Swarm, and yes they are fairly small subs. You mentioned Harry Pearson above... his magazine (well it was no longer technically "his" at the time) gave it a "product of the year" award a few years ago. The modal smoothing seems to hold up pretty much throughout the room in most cases. Only had one case where the user had to try a few different configurations, and one of Todd Welti's configurations did the trick for him. It was a small recording studio.

 

[DDF]

Fortunately the world has decided that omni woofers are to be the norm. Even most "full bandwidth" dipole speakers transition to monopole bass drivers. I think dipole subwoofers have joined the dodo bird, as they should. There are a couple of cardioid woofers out there somewhere I think.

Dipoles/cardiods are sometimes claimed superior due to "exciting fewer room modes". johnk once provided interesting analytical examples showing how this is often a bad thing as fewer modes mean less uncorrelated averaging across all the modes and can easily result in worse dominant peaks & dips from the room @ the listening area.

 

[j_j]

Ime there is a definite rising trend as we go down in frequency in many rooms, but in practice it's not a nice neat rise, as it is subject to the modal behavior of the room. Perhaps there are situations where "the room [has] a peak", but in my experience rooms have multiple peaks at low frequencies, and those peaks move to different frequencies as the position of listener or loudspeaker changes.

A room's basic modes will not change with speaker location, but how you drive them (or not) will change.

But you're confusing two things here, room response and woofer response.

Usually, DI is pretty monotonically increasing as frequency goes down. But with some subs, that's not the case. If a place where the *POWER RESPONSE* goes up faster than expected, even positing a reasonable direct component happens to be at a room mode (yes, I've seen this, indeed) you can get some serious shaking goin' on. And I don't mean tight, controlled bass.

 

[Duke]

A room's basic modes will not change with speaker location, but how you drive them (or not) will change.

The peak-and-dip pattern that is the consequence of speaker + room interaction changes with speaker location. But the speaker is not changing, so it must be the room's effect that is changing.

But you're confusing two things here, room response and woofer response.

I probably wasn't as precise with my wording as I could have been.

My understanding is that, perceptually, speakers + room = a "system" in the bottom couple of octaves; in other words, the ear/brain system doesn't perceive a direct sound from the subwoofer followed by a reverberant field, at least not in the size rooms most of us listen in at home.

As for my confusion about room response and woofer response, I think it's possible for them to "work together" instead of the one ruining the other. EQ optional.

Usually, DI is pretty monotonically increasing as frequency goes down. But with some subs, that's not the case. If a place where the *POWER RESPONSE* goes up faster than expected, even positing a reasonable direct component happens to be at a room mode (yes, I've seen this, indeed) you can get some serious shaking goin' on. And I don't mean tight, controlled bass.

My modeling program shows a 15" woofer's DI going to zero somewhere between 180 and 200 Hz. If that's correct, then DI is not changing down in the subwoofer region (ballpark 80 Hz and below). So if there is a rising response and/or peaking in the subwoofer region, it is not because the directivity index is changing. The directivity index has already long since finished changing by the time we get into the subwoofer zone.

 

[j_j]

The peak-and-dip pattern that is the consequence of speaker + room interaction changes with speaker location. But the speaker is not changing, so it must be the room's effect that is changing.

You are driving the same system from a different point.

My understanding is that, perceptually, speakers + room = a "system" in the bottom couple of octaves; in other words, the ear/brain system doesn't perceive a direct sound from the subwoofer followed by a reverberant field, at least not in the size rooms most of us listen in at home.

As far as the ear is concerned, mostly. The only exception is from sudden transients. Then you can still have some detection of leading edges. That's a good thing, actually, in the wild.

My modeling program shows a 15" woofer's DI going to zero somewhere between 180 and 200 Hz. If that's correct, then DI is not changing down in the subwoofer region (ballpark 80 Hz and below). So if there is a rising response and/or peaking in the subwoofer region, it is not because the directivity index is changing. The directivity index has already long since finished changing by the time we get into the subwoofer zone.

Now try it for a subwoofer using a passive radiator, or even a heavily tuned subwoofer as opposed to a brute-force direct radiator.

 

[Bjorn]

It's a bit strange seeing claims based on studies that we to a large degree are able to hear through room issues, but at the same time regularly hearing that room treatment, and even with constant directivity speakers, is the greatest upgrade people have ever experienced.

For me, the idea that we can hear through room problems is related only to being able to enjoy music to a certain extent but completely overlooks the meaning of quality. IMO it's basically lowering the standard to something very mediocre. I have had constant directivity speakers for years now, and placed in different rooms and I have never experienced room treatment not being a huge upgrade. However, a lot of treatment out there today are poor. Typically very band-limited, not effective at low frequencies and more simple scattering units rather than diffusers.

Multiple subwoofers used alone is IMO also a huge compromise. Both because it doesn't work in the area where we are the most sensitive to ringing and decay but also because it seldom sounds as precise and coherent as having one low frequency source. Latter is obviously dependent on several factors like placement, integration, signal time alignment, crossover frequency, etc.

 

[b1daly]

Yes, the perceived tonality of the source changes from one acoustic environment to another.

Can you? Can you make such a determination upon being presented with an unknown speaker in an unknown room? I can make some presumptions but not a determination.

That is room dependent and of a different (smaller) magnitude than moving from one acoustic space to another.

I like to refer to a common experience of mine: Being hailed by a friend from across the main space of the Grand Central Terminal. First, I hear the address (my name) from afar but I can only recognize who it is by sight. However, as he and I approach each other, I can increasingly identify his characteristic voice but it is highly colored by the influence of that reverberant space. When we do come face-to-face and I hear him almost exclusively by direct sound (my ear brain now easily suppressing attention to the reverberation), he sounds as he ever does when in close proximity. That shift occurs in smaller and less imposing acoustical spaces but to a much lesser degree.

There is an aspect of your observation about it being easier to identify a voice as it moves closer in a reverberant space which makes it not so relevant to the point Cosmik is making. In your example the source is moving and listener is still. It would make sense for the sound (and identify perception) to change as it moves towards. We should be very interested in any object moving towards us, and the closer it gets the more important the task of identifying it becomes.

The effect under discussion is that when we move in a reverberant space our localization system allows us to percieve a sound source as unmoving and unchanging in its primary sound signature.

There are limits to how much our brains compensate but they are shockingly liberal.

The problem for speakers is that they both are a sound generating object and devices that aim to represent with some fidelity other sound generating objects. This presents a problem that can only be solved by compromise.

 

[b1daly]

I think there is a "confusion of concerns" that often happens in discussions of audio (re)production. When it comes to home/pleasure listening the main concern is the subjective experience of the listener. The hope is that the listener has a good experience.

The most interesting aspect of the research the Mr. Toole works on is that they connected measured observations with subjective preferences, and showed a high correlation between the two categories of observations.

In addition to the question proposed by the OP, whether these room correction systems are included simply as a marketing ploy, I think an important question is, why does do users attempt to use these systems?

If you divide listeners into roughly two camps, audiophiles and civilians, my hunch would be that a civilian would be most likely to use the built in room correction system in a typical AVR, if they do at all, because it said to do so in the manual.

Audiophiles I'm sure are susceptible to the suggestion that room correction is needed by default, but let's assume that the discerning audiophile is actually responding to a perceived deficiency in their system.

The "civilian" category of listeners usually have no idea how to run their AVR. If they manage to access any controls at all on the convoluted menus, it is virtually certain that any change to the audio will be for the worse. The crazy DSP on these units has perplexed many people, who cannot understand why they can't understand the words in movies, because they have the wrong decoder on, or they have "rock concert" reverberation set to on.

My experience as a sound engineer is that it is vastly easier to change sound for the worse than for the better. In my view, this would point to simpler to understand interfaces on AVRs that default to the most uncolored sound possible.

Then providing front panel tone controls with well-selected corner frequencies will cover 90% of the cases. The problem of selecting the right codec for movies is harder, I don't have a good idea on that. But room correction is out of the question, just pointless. It will almost certainly result in worse sound.

For more interested "audiophile" listeners, who have time and inclination to learn the details of their playback systems and to develop their levels of listening discernment, perhaps simple room correction DSP could work, but my guess is that most attempts to use this approach lead to significantly worse outcomes.

What I think would be most helpful would be access to graphic EQs, or perhaps full parametric EQ, with really good interfaces. The functioning of the interface makes a huge impact on how effective an EQ is. A hard to use EQ, with hidden menus, and poor control resolution is of minimal help. An ideal EQ has immediate access to parameters, and good "control" resolution. Meaning, the movement of the control, lets say the frequency for a parametric EQ, results in a useful change in sound. Many controls do not allow for fine enough resolution which is required to target frequencies precisely.

The "control resolution" on the frequency gain has a huge impact as well. Many pro graphic equalizers have a setting that will change maximum adjustment (fader at end of range) from +/- 6db to +/-12db. Using the EQ at these different settings leads to very different adjustments on the part of the user.

The overall thrust of my suggestions (which will be adopted by probably no one ever) is to allow the user to tailor their system to their preference by ear. Part of this is encouraging people to trust their own perceptions. To tune in to what aspects of sound they like or don't like. Then they can use an EQ to make adjustments by ear.

While I'm sure this will lead to some strange choices, I think with some education and encouragement users will ultimately come up with a system that provides a more pleasing subjective experience that monkeying around with automatic dsp corrections of myriad types.

There are other very simple things that will have much more impact than any room correction involving speaker placement and room treatment. Again some education will be helpful. A starting point would be the main stereo speakers, then suggestions for placement of additional speakers. To find good positions for the speakers is a pain, but with a friend and a little leeway for placement, huge differences in sound representation will result.

As far as treatment goes, just have a mix of absorbent and reflective surfaces in a listening room can cover a lot of sins. Things like huge glass windows might be hopeless, but otherwise placing normal household objects and furnishing in a room can usually provide a decent level of sound treatment, as long as the room is not too large.

The overall thrust of my suggestions is that the best way to make adjustments to sound in a home system is by ear. While this is not easy, by definition it will help lead a listener to a better subjective experience if they are assisted with sensible suggestions and encouragement to trust their own ears.

 

[Floyd Toole]

I think there is a "confusion of concerns" that often happens in discussions of audio (re)production. When it comes to home/pleasure listening the main concern is the subjective experience of the listener. The hope is that the listener has a good experience.

The most interesting aspect of the research the Mr. Toole works on is that they connected measured observations with subjective preferences, and showed a high correlation between the two categories of observations.

In addition to the question proposed by the OP, whether these room correction systems are included simply as a marketing ploy, I think an important question is, why does do users attempt to use these systems?

If you divide listeners into roughly two camps, audiophiles and civilians, my hunch would be that a civilian would be most likely to use the built in room correction system in a typical AVR, if they do at all, because it said to do so in the manual.

Audiophiles I'm sure are susceptible to the suggestion that room correction is needed by default, but let's assume that the discerning audiophile is actually responding to a perceived deficiency in their system.

The "civilian" category of listeners usually have no idea how to run their AVR. If they manage to access any controls at all on the convoluted menus, it is virtually certain that any change to the audio will be for the worse. The crazy DSP on these units has perplexed many people, who cannot understand why they can't understand the words in movies, because they have the wrong decoder on, or they have "rock concert" reverberation set to on.

My experience as a sound engineer is that it is vastly easier to change sound for the worse than for the better. In my view, this would point to simpler to understand interfaces on AVRs that default to the most uncolored sound possible.

Then providing front panel tone controls with well-selected corner frequencies will cover 90% of the cases. The problem of selecting the right codec for movies is harder, I don't have a good idea on that. But room correction is out of the question, just pointless. It will almost certainly result in worse sound.

For more interested "audiophile" listeners, who have time and inclination to learn the details of their playback systems and to develop their levels of listening discernment, perhaps simple room correction DSP could work, but my guess is that most attempts to use this approach lead to significantly worse outcomes.

What I think would be most helpful would be access to graphic EQs, or perhaps full parametric EQ, with really good interfaces. The functioning of the interface makes a huge impact on how effective an EQ is. A hard to use EQ, with hidden menus, and poor control resolution is of minimal help. An ideal EQ has immediate access to parameters, and good "control" resolution. Meaning, the movement of the control, lets say the frequency for a parametric EQ, results in a useful change in sound. Many controls do not allow for fine enough resolution which is required to target frequencies precisely.

The "control resolution" on the frequency gain has a huge impact as well. Many pro graphic equalizers have a setting that will change maximum adjustment (fader at end of range) from +/- 6db to +/-12db. Using the EQ at these different settings leads to very different adjustments on the part of the user.

The overall thrust of my suggestions (which will be adopted by probably no one ever) is to allow the user to tailor their system to their preference by ear. Part of this is encouraging people to trust their own perceptions. To tune in to what aspects of sound they like or don't like. Then they can use an EQ to make adjustments by ear.

While I'm sure this will lead to some strange choices, I think with some education and encouragement users will ultimately come up with a system that provides a more pleasing subjective experience that monkeying around with automatic dsp corrections of myriad types.

There are other very simple things that will have much more impact than any room correction involving speaker placement and room treatment. Again some education will be helpful. A starting point would be the main stereo speakers, then suggestions for placement of additional speakers. To find good positions for the speakers is a pain, but with a friend and a little leeway for placement, huge differences in sound representation will result.

As far as treatment goes, just have a mix of absorbent and reflective surfaces in a listening room can cover a lot of sins. Things like huge glass windows might be hopeless, but otherwise placing normal household objects and furnishing in a room can usually provide a decent level of sound treatment, as long as the room is not too large.

The overall thrust of my suggestions is that the best way to make adjustments to sound in a home system is by ear. While this is not easy, by definition it will help lead a listener to a better subjective experience if they are assisted with sensible suggestions and encouragement to trust their own ears.

Thanks for a controlled and rational contribution. I agree that listeners should be encouraged to trust their ears, and make adjustments - to compensate in real time for spectral variations in recordings, and also to find a spectral balance that is found to be pleasant over the long term. This is not a new idea. I have long advocated the use of bass, treble and tilt controls, but the first proponent was Peter Walker of Quad, who had these three controls in his preamp (even though his loudspeakers were very neutral). He also had a low-bass adjustment, realizing the importance of taming aggressive room resonances (booms).

It needs to be emphasized that this spectral manipulation exercise will be most rewarding if one begins with neutral loudspeakers, those without audible resonances (that color everything that is listened to) and that exhibit smoothly controlled directivity as a function of frequency, so that the reflected sound field has a timbral resemblance to the direct sound. This is the most difficult part. As I have pointed out with nauseating frequency, neutral loudspeakers can be recognized in a comprehensive set of anechoic measurements, the spinorama format being especially useful. These data are scarce, marketing claims are abundant, and typical subjective reviews are unreliable. Into this unsatisfying scenario come the "room EQ" advocates, claiming to make any loudspeaker, at any location, in any room into something resembling "perfection". It is simply not possible.

You are right about acoustical treatments. Many common furnishings are acoustically functional as absorbers and scattering objects. I use these "stealth" treatments in my own multipurpose 9.4.6 channel room. It sounds just fine.

However, again being repetitive, room EQ is probably essential to address room resonances and adjacent boundary effects at frequencies below about 400-500 Hz. If neutral loudspeakers were selected, employing some of these EQ schemes above those frequencies may degrade the inherent performance of the loudspeakers. This is obviously not a satisfactory situation. Here is the last illustration in the 3rd edition of my book:

 

[j_j]

However, again being repetitive, room EQ is probably essential to address room resonances and adjacent boundary effects at frequencies below about 400-500 Hz. If neutral loudspeakers were selected, employing some of these EQ schemes above those frequencies may degrade the inherent performance of the loudspeakers. This is obviously not a satisfactory situation. Here is the last illustration in the 3rd edition of my book:

I think that's accurate, but a good correction algorithm should be able to tell when NOT to correct. Long-window FFT's ignore the very basics of perception, for instance, in addition to the typical acoustics of a listening room, and no, they are not an improvement (wince).

 

[j_j]

It's a bit strange seeing claims based on studies that we to a large degree are able to hear through room issues, but at the same time regularly hearing that room treatment, and even with constant directivity speakers, is the greatest upgrade people have ever experienced.

I'm not sure why that's strange. At frequencies above the point where the detection on the cochlea happens BEFORE the room response arrives, you can hear all of the direct, early reflections, and diffuse sound separately to some extent. So you can "hear through" things. That's why you can understand speech in an average room if the speaker is 10 feet away. You're outside the room's critical distance, but you have no trouble understanding speech.

BUT the room can mask parts of the direct signal that comes later. So you both can and can't "hear through" depending on what you want to hear. Your discussion is a massive oversimplification.

 

[b1daly]

It's a bit strange seeing claims based on studies that we to a large degree are able to hear through room issues, but at the same time regularly hearing that room treatment, and even with constant directivity speakers, is the greatest upgrade people have ever experienced.

For me, the idea that we can hear through room problems is related only to being able to enjoy music to a certain extent but completely overlooks the meaning of quality. IMO it's basically lowering the standard to something very mediocre. I have had constant directivity speakers for years now, and placed in different rooms and I have never experienced room treatment not being a huge upgrade. However, a lot of treatment out there today are poor. Typically very band-limited, not effective at low frequencies and more simple scattering units rather than diffusers.

Multiple subwoofers used alone is IMO also a huge compromise. Both because it doesn't work in the area where we are the most sensitive to ringing and decay but also because it seldom sounds as precise and coherent as having one low frequency source. Latter is obviously dependent on several factors like placement, integration, signal time alignment, crossover frequency, etc.

There is no getting away from the fact that we do listen to both speaker and room together as a system. Speaker placement, room shape, and treatment are all critical. But I think as practical concern there is a “window” of acceptable listening environments. The room just needs to be “good enough” for an acceptable listening experience. Whithin this threshold the ability to “hear through the room” helps the brain integrate the whole listening environment and extract the signal.

There is a paradox involved in the use of speakers to generate a fascimile of a live performance, which one of the above commenters was pondering.

He was questioning whether there were different “rules of acoustics” (my phrasing) in designing a performance environment vs a listening environment?

Yes and no. The obvious difference is the relative size.

The paradox is as follows. The acoustic signature of a performance space is inseparable from the performance. The audience experience is based on the whole, and the performance space is the ultimate object upon which the artists ply their craft. In the same way a violin player learns to control the vibration of the instrument to vibrate the adjacent air, the ensemble endeavors to excite the air in a performance space to generate the ultimate event the audience experiences.

For the playback system attempting to represent a similar experience in a specific listening environment, this presents a virtually impossible task.

If we have a recording that captures and represents faithfully the original sonic signature of the original performance, then a more “treated” space could be ideal. Most of the ambience reduced, with what is left being spectrally neutral.

But for this to work, the recording must be designed to have the original ambience represented.

However, it is inevitable that the average listening space is not a relatively “dead,” controlled space. It is instead a room with its own sonic signature.

Because producers of recordings endeavor to create recordings for the “real world” they understand that the final listener experience will be the combination of the recorded ambience and the playback environment ambience. There is no perfect solution. It requires an educated guess on the part of the producer.

One could apply some of the acoustic principles of designing a performance space to a listening space. This would put the focus on creating a more “live” sounding space, with an esthetically pleasing sound.

It’s not hard to see the problem with this: it puts the ultimate expression of the artist out of reach. The expression of the room designer dominates. If the listener was able to create their own recordings just for this space it could be interesting. But it would be a limited space.

Ultimately the listener of a recording experiences the sum of the signal and space. This requires a lot of “fudge factor.” A listening space must have some ambience to be effective. It is the ability of our brain to separate the direct sound of the speaker from reflected sound that enables this kludgey system to work as well as it does.

 

[stereo01]

Thanks for a controlled and rational contribution. I agree that listeners should be encouraged to trust their ears, and make adjustments - to compensate in real time for spectral variations in recordings, and also to find a spectral balance that is found to be pleasant over the long term. This is not a new idea. I have long advocated the use of bass, treble and tilt controls, but the first proponent was Peter Walker of Quad, who had these three controls in his preamp (even though his loudspeakers were very neutral). He also had a low-bass adjustment, realizing the importance of taming aggressive room resonances (booms).

It needs to be emphasized that this spectral manipulation exercise will be most rewarding if one begins with neutral loudspeakers, those without audible resonances (that color everything that is listened to) and that exhibit smoothly controlled directivity as a function of frequency, so that the reflected sound field has a timbral resemblance to the direct sound. This is the most difficult part. As I have pointed out with nauseating frequency, neutral loudspeakers can be recognized in a comprehensive set of anechoic measurements, the spinorama format being especially useful. These data are scarce, marketing claims are abundant, and typical subjective reviews are unreliable. Into this unsatisfying scenario come the "room EQ" advocates, claiming to make any loudspeaker, at any location, in any room into something resembling "perfection". It is simply not possible.

You are right about acoustical treatments. Many common furnishings are acoustically functional as absorbers and scattering objects. I use these "stealth" treatments in my own multipurpose 9.4.6 channel room. It sounds just fine.

However, again being repetitive, room EQ is probably essential to address room resonances and adjacent boundary effects at frequencies below about 400-500 Hz. If neutral loudspeakers were selected, employing some of these EQ schemes above those frequencies may degrade the inherent performance of the loudspeakers. This is obviously not a satisfactory situation. Here is the last illustration in the 3rd edition of my book:

Just wanted to take a moment to say thanks for helping myself as a non-scientist but music lover understand some basic concepts about acoustics which has allowed me to have a listening room and equipment that brings me great joy everyday.

 

[Floyd Toole]

Because producers of recordings endeavor to create recordings for the “real world” they understand that the final listener experience will be the combination of the recorded ambience and the playback environment ambience. There is no perfect solution. It requires an educated guess on the part of the producer.

Correct. This is why it is important for at least the mastering, if not the mixing, of recordings be done in spaces that approximate average domestic listening rooms. This sometimes happens, but not always. This is a component of the circle of confusion.
In the superposition of a large recorded space on a small listening room, it is fortuitous that the larger space usually wins the perceptual race. Small rooms can be made to sound large, but large rooms cannot be made to sound small. Obviously all of this is much more satisfactory with multichannel originals, but upmixed stereo can be very rewarding from the spatial perspective.

 

[j_j]

Small rooms can be made to sound large, but large rooms cannot be made to sound small.

This is completely required by the acoustical physics of the spaces. None the less, I have been contradicted many times, by many people who insist it's the other way around.

Please don't ask me why, nobody can explain that contrary statement, not even as far as addressing critical distance, but for a while, it was rampant in some quarters.

But yes, I'm glad you said that. Now they can yell at you and I'll just watch and laugh at them.

 

[Floyd Toole]

This is completely required by the acoustical physics of the spaces. None the less, I have been contradicted many times, by many people who insist it's the other way around.

Please don't ask me why, nobody can explain that contrary statement, not even as far as addressing critical distance, but for a while, it was rampant in some quarters.

But yes, I'm glad you said that. Now they can yell at you and I'll just watch and laugh at them.

I can take it . The real problem with the "reverse" situation is in movie sound, where large cinemas cannot deliver intimate "whispering secrets in the ear" kind of intimacy - the large space is permanently superimposed. This is one reason why, ultimately, in the acoustical context, home theater wins over going to the movies - the other is simply potentially much better sound quality. There is no critical distance in home listening rooms, so things are more straightforward. This is something that has not yet dawned on a lot of "traditional" acousticians.

 

[j_j]

I can take it . The real problem with the "reverse" situation is in movie sound, where large cinemas cannot deliver intimate "whispering secrets in the ear" kind of intimacy - the large space is permanently superimposed. This is one reason why, ultimately, in the acoustical context, home theater wins over going to the movies - the other is simply potentially much better sound quality. There is no critical distance in home listening rooms, so things are more straightforward. This is something that has not yet dawned on a lot of "traditional" acousticians.

There's a third huge advantage to home theaters, too, in that the time delays are much more suited to creating phantom images with fewer loudspeakers.

 

[Ron Texas]

A very interesting thread. My main take away is equalize below 400-500 hz, lowering the peaks. Ignore narrow dips. I just sent off for a MiniDSP microphone, because I have tired of playing around with the problem with trial and error adjustments.