Should I worry about overdoing it?

[DanDan]

"Flat in an anechoic room is correct"
Perhaps we need to define 'correct'
Perhaps I am misunderstanding this statement, or there is an invisible presumed context?
i.e. Do we monitor what is on the recording, Flat Anechoic, AudioMetric Tools? Or do we monitor what the listeners will actually hear?
Or something in-between?
Afaik it is widely known and accepted that listening to flat response on axis in an anechoic space, be it a lab or outdoors, is unpleasant.
Similarly nobody mixes or listens for pleasure on Audiometric headphones. https://en-ie.sennheiser.com/audiometry
The sound delivered to my ears by Sennheiser 480 and HD650 headphones is remarkably similar to that delivered by B&K curved speakers in my pretty dead CR.
For me the concepts of 'right' and 'wrong' are often inadequate to describe obvious reality.
Or put it another way, to assume that to be 'right' necessitates an opposing view as 'wrong' eliminates the possibility of rational debate, fosters confirmations bias, and ultimately leads to an incomplete understanding of what is actually happening.
DD

 

[AudiocRaver]

So many variables.

Thought #1: It is extremely difficult - not impossible, but perhaps impractical for most people and listening rooms - to address all of these needs and concerns ideally. We prioritize, partly to a certain degree on - dare I say it? - personal preference, and partly to emulate theory and examples that fit our listening needs best.

My own priorities: Soundstage and Imaging (SS&I) are absolute king, all else follows. While I do not quite understand how that is not the case for everyone who has heard how glorious it can be, I have to swallow my pride and acknowledge that listening experience and favorite music types play a big role. Or movies rather than music.

My thoughts on LF absorption. I must agree with Mark Seaton’s views on this, that “too much” LF absorption is an asymptotically-approached limit that is rarely if ever achieved. The uncovering and revelation of minute detail in a recording by increasing LF absorption is a no-going-back eye opener that I have experienced.

Matt’s comments on spaciousness is an area I have not thought about or worked with specifically, although calling the range from 80 Hz to 500 Hz Low Frequencies does not seem accurate, as 262 Hz is middle C and the fundamentals of most instruments and voices land in that range. But this is an area that is new to me, so I will defer to Matt’s expertise until I am able to dig into it further.

Matt has also talked before about REAL LF (below 80 Hz??) spaciousness, which is an area that I cannot address and seems a lower priority to me. But, having experienced it some day, who knows, I may become a fanatic about it.

Dead End Live End (DELE) makes far more sense to me than LEDE, which makes no sense at all, but not as an all-encompassing design approach, more as a pattern with some useful concepts.

Haas was a fine fellow,, I knew him well LOL. I take issue with those who over-generalize his work, which is almost everyone, and I think he would agree with me. Maybe?? VERY early reflections (first few milliseconds) are strong enhancers to perception of signal direction, as discussed in a paper that Matt has provided a link to, not sure which thread that is in. Matt, maybe a repeat of that link? I have experienced it, and it makes sense from the perspective of biological advantage and evolution of human hearing. A reflection that arrives a few milliseconds after the first wavefront must come from within a few feet of the direction of the original wave, so it provides useful info to the hunter-gatherer trying to evade a stalking tiger. That example is my own viewpoint.

Reflections coming later, the ear has a TENDENCY to integrate with the direct signal, affecting timbre of the perceived direct sound, and definitely affecting SS&I. I take a little issue with those who say that above room transition we only hear the speakers, essentially ignoring the “integrated” early reeflections (5 to 20 mS or so). The psychoacoustical construction of SS&I is all about the brain determining direction, distance, size, etc. of a sound’s source, and that subtleties do matter. The brain is somewhat plastic and trainable. When you listen for minute SS&I details day in and day out for years, you start to hear things that you could not before.

The point here is that early reflections do affect our perception of SS&I, that even small reflections can make a big SS&I difference. WHICH reeflections to treat depend - as stated by others - on the speaker, the room, the room’s purpose, the delay and direction, and the listener’s experience and preferences.

Agreed that a tracking/mixing environment is likely to call for more reflection control, and that a home listening environment can benefit from the right early reflections, carefully applied, if the listener so chooses.

I like a fairly dead listening environment, music and movies, with emphasis on SS&I and inner recorded detail.

 

[Matthew J Poes]

"Flat in an anechoic room is correct"
Perhaps we need to define 'correct'
Perhaps I am misunderstanding this statement, or there is an invisible presumed context?
i.e. Do we monitor what is on the recording, Flat Anechoic, AudioMetric Tools? Or do we monitor what the listeners will actually hear?
Or something in-between?
Afaik it is widely known and accepted that listening to flat response on axis in an anechoic space, be it a lab or outdoors, is unpleasant.
Similarly nobody mixes or listens for pleasure on Audiometric headphones. https://en-ie.sennheiser.com/audiometry
The sound delivered to my ears by Sennheiser 480 and HD650 headphones is remarkably similar to that delivered by B&K curved speakers in my pretty dead CR.
For me the concepts of 'right' and 'wrong' are often inadequate to describe obvious reality.
Or put it another way, to assume that to be 'right' necessitates an opposing view as 'wrong' eliminates the possibility of rational debate, fosters confirmations bias, and ultimately leads to an incomplete understanding of what is actually happening.
DD

Hi DanDan,

Ok my first response contradicted itself so I’m editing this. I need to really respond on a laptop so I can be more careful.

Basically it’s more complex.

 

[Matthew J Poes]

Ok so the definite work on this topic comes from Toole at both Harman and the NRC. That work was focused on correlating the way a speaker under test in an anechoic chamber measured correlated with how it then measured in room, and further, if that was preferable. They didn’t test people listening in an an anechoic chamber and testing the listening curve. For this body of work we need to look at some theory that has been tested as true. For the latter issue, the preference curve, we need to mix this first issue with what we know about psychoacoustics and it’s relationship to common occurring phenomena.

As far as I know, nobody did preference curves in an anechoic chamber other than some very specific headphone curve research at Harman. That does suggest that you want a response to follows the preference curve of speakers. However it’s important to recognize how preliminary that work remains and that they keep learning new stuff about that. Why isn’t fully understood.

Ok first, why does a speaker measure the way it does in a room if it is flat anechoicly. As noted earlier, a speaker that measures flat in a reflection free environment will show a curve in room and the shape and slope of that curve depends on the speakers dispersion pattern and the rooms reflectivity. Because speakers tend to have a non-flat DI, especially at low frequencies and because rooms tend to have more reflections at low frequencies which are shorter in time than 1-2 periods, those low frequencies tend to become elevated. Highs do the opposite because rooms absorb more HF’s and the speakers tend to beam more. All sound sources often behave like this and we spend most of our time in small rooms so this is also a tonal expectation for humans. That goes into the psychoacoustic idea.

It isn’t certain, but believed, that we have evolved to prefer the sound we hear in small acoustic spaces. Maybe because we used to live in caves, then small huts and tents, and eventually relatively small homes. Who knows. What we know is that on average people prefer the curve we commonly see a speaker make when it measures flat in an anechoic chamber. The bass is the tricky thing. While some of the issue can be explained by the fact that a speaker is normally omnidirectional at low frequencies, there is more to it. It takes 2-3 periods for us to register tone at low frequencies. A 100hz tone has a period of 10ms which is about 11 feet. That means any sound that arrives within up to 33 feet or 30ms is perceived as the same tone at 100hz. It’s longer at lower frequencies. This means that we perceive as the direct sound all sound arriving over a huge time frame which is acoustically many time larger than the rooms we listen in. That means that this extra energy boosts the bass. That is what we are used to hearing. Maybe we evolved to be less sensitive to bass because it’s always so elevated in these small spaces. Again, who knows. Not anything we can really study.

Listener preference curve in an anechoic environment. Ok I decided I shouldn’t try to say there is any science here because I realized I mixed two areas of research. I think that the preference would be to have a flat response down to a certain point and then elevate the bass. I don’t think this has been studied and I think the issue is complex. This goes back to psychoacoustics again. The omnimic pics up a lot of reflected energy that our brain is able to distinguish and ignore. That means at the mid and high frequencies the brain is able to distinguish something the mic can’t in the steady state response. The tonal balance we hear is different from what we measure. Things are different at low frequencies. The length of a period starts to become large relative to the dimensions of a room and as such what we hear becomes a multiple of the room dimensions. That means our perception of direct sound at low frequencies matched the steady-state better (still not perfect). So if you create an anechoic environment, probably you need to goose the bass. What I can’t say is how much and where the inflection point should be. I think the research isn’t there. If you know of some please share, but I think it needs to be pretty sophisticated. The key is that the rooms reflective properties needs to be well characterized and the speakers free space measurements known.

I define anechoic as reflection free or free space. I consider most studies to be semi-anechoic. I would argue that for this whole phenomena to work like I’ve discussed, the first reflection at 50hz would need to be 2-3 times the length of a period. Something like 45-50 feet, or about 40-45ms. If the first reflection was down in level it might be ok but how down In level is enough? I would imagine at least 30-40 decibels lower in level and delayed by at least one period. This is why anechoic chambers aren’t anechoic at very low frequencies. The delay is solely a function of the dimensions of the room. How many studios have minimum dimensions of 20-30 feet? Width and length maybe, but the ceilings are often lower than that.

 

[DanDan]

That's a whole lotta doubts and aspersions! Some interesting points though.
If you have not read this guy before I sense that you will just love this......https://www.soundonsound.com/sound-advice/how-we-hear-pitch
An imposed listening curve in an effectively anechoic CR has been extensively tested and reevaluated periodically over years. Subtle alterations of the curve by even 0.5dB are audible. Different way points create obviously different tonality. Ultimately B&K wins. This is hardly surprising. That particular combination of LF boost, but curtailed, with the long slow HF roll off, seems robust. The Harmon Headphone curve, HD650, are close to it. Many of us have taken this journey, ending up with almost identical curves. Here's a well documented carefully done one.
https://www.gearslutz.com/board/studio-building-acoustics/817205-my-listening-room.html
In any normal listening environment, speaker or headphone, HF is diminished by at least 3dB. If one mixes in a HF flat scenario, the result will and repeatedly does, sound dull.
We respond in exact inverse to FR deviations from the 'norm' which is far from flat. Again, oddly, we do not do the same regarding reverb or reflections.
DD

 

[Matthew J Poes]

What research has their been published on anechoic listening curves? I’m just. It familiar with such literature. I mean, I think we already know I take a pedantic view on what is anechoic so it might just be how I’ve classified what I read.

B&K’s curve, from what I was told by an engineer at B&K was just an extension of the earlier work looking at how a flat measuring speaker in anechoic conditions measured in a real room. Outside of quick gut check listening, it wasn’t my impression they ever did any rigorous listening test experiments. Do you have any more information on the history of their curve?

And sorry for any aspersions, not trying to attack any specific persons credibility here.

It seems surprising that the the reverberation sound of a control room doesn’t impact how a mix is ultimately made.

 

[Matthew J Poes]

So many variables.

Thought #1: It is extremely difficult - not impossible, but perhaps impractical for most people and listening rooms - to address all of these needs and concerns ideally. We prioritize, partly to a certain degree on - dare I say it? - personal preference, and partly to emulate theory and examples that fit our listening needs best.

My own priorities: Soundstage and Imaging (SS&I) are absolute king, all else follows. While I do not quite understand how that is not the case for everyone who has heard how glorious it can be, I have to swallow my pride and acknowledge that listening experience and favorite music types play a big role. Or movies rather than music.

My thoughts on LF absorption. I must agree with Mark Seaton’s views on this, that “too much” LF absorption is an asymptotically-approached limit that is rarely if ever achieved. The uncovering and revelation of minute detail in a recording by increasing LF absorption is a no-going-back eye opener that I have experienced.

Matt’s comments on spaciousness is an area I have not thought about or worked with specifically, although calling the range from 80 Hz to 500 Hz Low Frequencies does not seem accurate, as 262 Hz is middle C and the fundamentals of most instruments and voices land in that range. But this is an area that is new to me, so I will defer to Matt’s expertise until I am able to dig into it further.

Matt has also talked before about REAL LF (below 80 Hz??) spaciousness, which is an area that I cannot address and seems a lower priority to me. But, having experienced it some day, who knows, I may become a fanatic about it.

Dead End Live End (DELE) makes far more sense to me than LEDE, which makes no sense at all, but not as an all-encompassing design approach, more as a pattern with some useful concepts.

Haas was a fine fellow,, I knew him well LOL. I take issue with those who over-generalize his work, which is almost everyone, and I think he would agree with me. Maybe?? VERY early reflections (first few milliseconds) are strong enhancers to perception of signal direction, as discussed in a paper that Matt has provided a link to, not sure which thread that is in. Matt, maybe a repeat of that link? I have experienced it, and it makes sense from the perspective of biological advantage and evolution of human hearing. A reflection that arrives a few milliseconds after the first wavefront must come from within a few feet of the direction of the original wave, so it provides useful info to the hunter-gatherer trying to evade a stalking tiger. That example is my own viewpoint.

Reflections coming later, the ear has a TENDENCY to integrate with the direct signal, affecting timbre of the perceived direct sound, and definitely affecting SS&I. I take a little issue with those who say that above room transition we only hear the speakers, essentially ignoring the “integrated” early reeflections (5 to 20 mS or so). The psychoacoustical construction of SS&I is all about the brain determining direction, distance, size, etc. of a sound’s source, and that subtleties do matter. The brain is somewhat plastic and trainable. When you listen for minute SS&I details day in and day out for years, you start to hear things that you could not before.

The point here is that early reflections do affect our perception of SS&I, that even small reflections can make a big SS&I difference. WHICH reeflections to treat depend - as stated by others - on the speaker, the room, the room’s purpose, the delay and direction, and the listener’s experience and preferences.

Agreed that a tracking/mixing environment is likely to call for more reflection control, and that a home listening environment can benefit from the right early reflections, carefully applied, if the listener so chooses.

I like a fairly dead listening environment, music and movies, with emphasis on SS&I and inner recorded detail.

Everyone seems to define bass differently. In acoustics it’s not uncommon to simply break up the bandwidth of human hearing into bass and treble and to set the divider at 1khz. In the audio world we don’t talk like that, but out of habit I do. Geddes always did when I would talk to him and then later when I began taking courses a lot of my professors did too.

Low frequency spaciousness is actually referring to a phenomena down to only about 50-70hz. Below that point there is both very little musical information and an ever weaning ability to detect the phase difference in laterally separated sources. David Griesinger is the man who really studied and developed this concept and in all fairness, the science is a lot more conceptual. I was recently talking to Todd Welti about this work, who pointed out that David never did any rigorous listening tests. As Todd put it, it is readily demonstrable that this effect is real using David’s contrived warble tones, but much more difficult to perceive in real music with real rooms. This brings into question how important the phenomena really is for our perception of and enjoyment of a musical performance. But then, @AudiocRaver when have I ever let a little thing like audibility stop me from a good scientific investigation of hearing.

If you really want to read up on it just look up his papers on listener envelopment and spaciousness. However I feel like this is something you really need to train your ears on what to hear. Spaciousness once you recognize it for what it is acoustically isn’t what you probably expect. I mean, for me, I didn’t know how to describe it but was sure I knew what it was. Once. Created a contrived experiment that allowed me to essentially turn it on and off, I had a different perception of what spaciousness is. I still can’t describe it to someone. You just have to hear it to get it.

Toole writes about the concept in a paper I have shared before. But he points out that we address the need because the lower limit is 100hz and we cross subs below that. He gives it all of that much attention in his article and I think none in his books. David argues that the perceptual limit is more like 70hz and maybe lower (and no listening tests have confirmed this beyond David’s warble tones). That summing to mono corrupts the spatial information contained in these low frequencies. I think that his argument is that even if the limit were 100hz, the act of summing to mono impacts the audibility of this spatial information because of the crossover region, which would easily extend past 100hz. It would cause a strong in room cancelation effect of the -L and -R components produced by the mains.

I think it’s all very cool but I get that I like it for cerebral reasons. The audibility and improvement in musical enjoyment is low. Further, David has pointed out that the lack of knowledge about this topic leads many engineers to remove or never add the -L and -R components that allow for this spatial perception. @DanDan would be the man to ask if this is true. David’s concern is that outside his lexicon reverb unit and derivatives of it, most don’t contain “stereo bass.” He even figured out that Harman messed with his Algo and that some logic7 devices aren’t really logic7 as he created it. My understanding is that mic techniques also matter. I sent him a very simple recording of a pipe organ I had thought might have good spatial information and he analyzed the file and found there was no -L and -R component and bass was totally mono up to 150hz or so.

 

[DanDan]

"What research has their been published on anechoic listening curves? I’m just. It familiar with such literature."
Depends what you mean by 'research' and by 'published' and I have said nothing about Anechoic Listening curves, in your terms.
The tone of such suggests doubt, disbelief, and summary denigration of any evidence not fitting into those unilaterally imposed limits.

I consider jim1961 documented experimentation over a long period to be 'research' and 'published'.
https://www.gearslutz.com/board/studio-building-acoustics/817205-my-listening-room.html
As I would my own considerable efforts and results and public statements over years.
Andre Vare frequently recommends B&K. Sonarworks has it built in. Dirac Live has a tilted recommended curve.
There is myriad evidence. Or you could just take on board a simple summary of my two years trial and error here.
I did some Beta fro DL and Sonar. More importantly I experimented specifically with Translation. It is essential that my Mixes and Masters sound similar everywhere.
So by simple repeated listening comparisons I compared the sound in my CR to three different systems in three different untreated rooms, and to headphones.
In all cases HF roll off was absolutely necessary to get any similarity in tone between CR and 'real' rooms.
This could be reduced by adding a LF boost.
But overall, time and time again, the overall tilt is about 6dB. This tallies well with B&K and Sonarworks researched and published curves.
My empirically observed, heard reality, is exactly the same as the extensive research.

I consider this to be fact. It is easily 'proven' if one has access to a reasonably treated room and a computer.
Eq the on axis listener spot in the CR/Listening room to 'Flat'. Listen. Play the same music in an untreated room.
There will be no similarity. Now gradually change the CR Eq until they do match as much as possible.
It is extremely unlikely that anyone trying this will get different results from B&K, Sonar, Hodas, DL, Vare, Me.

Olive:-

" The preferred in-room loudspeaker response is a smooth curve from 20 to 20 kHz with about a 9-10 dB downward tilted slope."
Read more at https://www.innerfidelity.com/conte...man-listener-target-curve#wyGb0rUP46D1TgFU.99

Bob Hodas:- "The "Flat Response" Myth
Many audio professionals assume, not unreasonably, that the whole purpose of room tuning, whether acoustically or through EQ, is to make the room "flat". In fact, I have yet to find an engineer or studio owner who actually wanted a "flat" room. Experience shows that a flat room has no personality and is no fun to work in. Equally important, working in a flat room does not necessarily ensure a recording that sounds good elsewhere."

I am surprised that you are not familiar with the B&K survey/research. It is a mainstay of what many of us have been pointing out for years. https://www.bksv.com/media/doc/17-197.pdf

It is indeed surprising that Pros, 'hear through' different amounts of liveliness and consistently do not apply inverse amounts of ambience.
There is research on this, probably to your strict requirements. Try the 90's, probably AES. In the meantime you could chose to believe it because I saw it quoted by someone I trust.
More importantly it tallies with my extensive experience. I have mixed outside of CRs as much as in them.

DD

 

[DanDan]

That spaciousness post just appeared here. Things are out of sequence. No pasa nada, IMO the meandering chat is intriguing.
I met David here in Ireland once. It was gratifying to hear that the 480L had no real similarities to any of the others, and was still his personal favourite.
In Mastering I frequently encounter narrow mixes. To widen I tend to use M/S Eq. This Side boost often works best in the same zone mentioned, i.e. around middle C and it's Octave above. Orchestral Recordings could have Basses, Bass Drum, off centre. The subsequent wash of reflections is definitely stereo. Similarly, free from Vinyl restrictions many of us Mix Bass elements to one side or another. A Swedish GS Fanatic insisted this was all heresy, as there is no bass below 80Hz.
A language fundamentalist might insist there is no such thing as a Double Positive.
Yeah Right.
DD

 

[Matthew J Poes]

"What research has their been published on anechoic listening curves? I’m just. It familiar with such literature."
Depends what you mean by 'research' and by 'published' and I have said nothing about Anechoic Listening curves, in your terms.
The tone of such suggests doubt, disbelief, and summary denigration of any evidence not fitting into those unilaterally imposed limits.

I consider jim1961 documented experimentation over a long period to be 'research' and 'published'.
https://www.gearslutz.com/board/studio-building-acoustics/817205-my-listening-room.html
As I would my own considerable efforts and results and public statements over years.
Andre Vare frequently recommends B&K. Sonarworks has it built in. Dirac Live has a tilted recommended curve.
There is myriad evidence. Or you could just take on board a simple summary of my two years trial and error here.
I did some Beta fro DL and Sonar. More importantly I experimented specifically with Translation. It is essential that my Mixes and Masters sound similar everywhere.
So by simple repeated listening comparisons I compared the sound in my CR to three different systems in three different untreated rooms, and to headphones.
In all cases HF roll off was absolutely necessary to get any similarity in tone between CR and 'real' rooms.
This could be reduced by adding a LF boost.
But overall, time and time again, the overall tilt is about 6dB. This tallies well with B&K and Sonarworks researched and published curves.
My empirically observed, heard reality, is exactly the same as the extensive research.

I consider this to be fact. It is easily 'proven' if one has access to a reasonably treated room and a computer.
Eq the on axis listener spot in the CR/Listening room to 'Flat'. Listen. Play the same music in an untreated room.
There will be no similarity. Now gradually change the CR Eq until they do match as much as possible.
It is extremely unlikely that anyone trying this will get different results from B&K, Sonar, Hodas, DL, Vare, Me.

Olive:-

" The preferred in-room loudspeaker response is a smooth curve from 20 to 20 kHz with about a 9-10 dB downward tilted slope."
Read more at https://www.innerfidelity.com/conte...man-listener-target-curve#wyGb0rUP46D1TgFU.99

Bob Hodas:- "The "Flat Response" Myth
Many audio professionals assume, not unreasonably, that the whole purpose of room tuning, whether acoustically or through EQ, is to make the room "flat". In fact, I have yet to find an engineer or studio owner who actually wanted a "flat" room. Experience shows that a flat room has no personality and is no fun to work in. Equally important, working in a flat room does not necessarily ensure a recording that sounds good elsewhere."

I am surprised that you are not familiar with the B&K survey/research. It is a mainstay of what many of us have been pointing out for years. https://www.bksv.com/media/doc/17-197.pdf

It is indeed surprising that Pros, 'hear through' different amounts of liveliness and consistently do not apply inverse amounts of ambience.
There is research on this, probably to your strict requirements. Try the 90's, probably AES. In the meantime you could chose to believe it because I saw it quoted by someone I trust.
More importantly it tallies with my extensive experience. I have mixed outside of CRs as much as in them.

DD

DanDan I think we actually are saying and believe the same thing and yet are still disagreeing. I agree with you that a speaker should measure with this tilted response in a listening room and in most studios. My point was what it would take to achieve the same tonal balance in a truest anechoic room. I think that is where we are disagreeing and it likely stems from my more pedantic view on anechoic. Let’s just call these types of studios as quasi anechoic.

I still believe that the preference curve isn’t so much about a specific tonal balance as it is about the natural response shape that a speaker with a given directivity and flat anechoic response tends to measure like in a normal moderately reflective room. The exception being bass boost, which I mentioned Before.

I think the exact tilt of the preference curve varies based on the rooms reflectivity and speakers directivity. Olive has hinted at this in one of his blog postings, but it’s admittedly not something anyone researched. I believe it is because most speakers actually have fairly similar directivity so generalizations work. When I have compared speakers with dramatically different directivity in my own room I do find my idea holds true, and I really can’t take credit for it, as the idea came from old research. I’ll post links when I get a chance as I think they are necessary.

I am sending an email to Olive and Welti later tonight and will be asking him about a related topic for something I’m working on. I can bring this up too. For what it’s worth, I am positive that Olives work and his comment is specific to the preference curve for normal listening rooms with normal levels of reflectivity. Not anechoic or semi-anechoic rooms. That wasn’t what those tests were about. I’ll ask him what he thinks, but knowing him, he will hedge his comments due to the lack of listening test research on the topic.

 

[Matthew J Poes]

That spaciousness post just appeared here. Things are out of sequence. No pasa nada, IMO the meandering chat is intriguing.
I met David here in Ireland once. It was gratifying to hear that the 480L had no real similarities to any of the others, and was still his personal favourite.
In Mastering I frequently encounter narrow mixes. To widen I tend to use M/S Eq. This Side boost often works best in the same zone mentioned, i.e. around middle C and it's Octave above. Orchestral Recordings could have Basses, Bass Drum, off centre. The subsequent wash of reflections is definitely stereo. Similarly, free from Vinyl restrictions many of us Mix Bass elements to one side or another. A Swedish GS Fanatic insisted this was all heresy, as there is no bass below 80Hz.
A language fundamentalist might insist there is no such thing as a Double Positive.
Yeah Right.
DD

David told me that not all vinyl is mono in the bass? Is that true. I had read so many times that it was. He gave me some specific albums to check out but I don’t own them and didn’t intent to go buy albums just to analyze them.

It’s good to know that he isn’t all wet and there are folks doing real stereo bass. I actually did an analysis of a lot of HD files from Qobuz recently and while most had very little of the -L and -R components, some did and some did in levels as strong as that of the L and R. When I bandwidth limited the tracks to only bass, I still found quite a bit in some of those.

 

[1_sufferin_mind]

In general, if you have a room with 4 corners, and you have 4 bass traps, will the effect be similar whether you place 1 in each corner vs all 4 in one corner, floor-to-ceiling? Sorry for the newbie questions. This is something I want to get into.

You and I both know there are many articles on the net about modes, acoustics, and treatments. I like the ones over at ASC because they apply to many treatments in general. Here’s a link.

Their Optimizing Tube Traps article is my go-to source for efficiently using bass traps. I’m extremely limited in my small 9x13x8 space, so I only treat the corners. In my soon-to-be 11x17x8 space, I may have a little more rope to play with for bass trapping on the front or sidewalls.

EDIT: And their ABC’s of ABC’s of Tube Traps article has very useful guides for choosing trap frequency relative to node and MLP locations. One of their consultants gave me a handy tip a while back: if you have trouble dialing in the room after you’ve treated the corners, play sweeps/music which excites the troublesome (bass) frequencies in question. Then carry each particular trap around the room’s perimeter untilit vibrates. Plant it there!