Acoustic treatment for my living room - Page 4

Or no treatment at all. Not all acoustic problems are solved best with acoustic treatment. In all cases, if you can remove the problem first, it is more ideal than leaving it there and then having to buy $140 books to figure out how to fix it . If it is fixable at all.....


Or being stuck on acoustic treatment as the only cure per above .

This is a systems problem and focusing on one chapter of the solution is just as wrong as someone focusing on a section in said chapter .

You have presented this SAME issue multiple times.

First, the treatment specified by the Erskine Group sourced by Quest is not simple porous absorption. It features an embedded membrane that functions similar to a VPR style absorber. The fact is that you seem to consistently miss this very salient point. So the comparison of apples to oranges is invalid.

Ironically, the use of such alternative treatment topologies as specified by the Erskine Group is exactly the type of creative alternative solution suitable to address given limitations that I have advocated as the proper course of action.

And what you emotionally believe is inconsequential to the physics of the situation.

You may also prefer to smear your body with chocolate pudding and sit listening to music or a movie in a yellow PVC raincoat. That personal preference has no objective bearing on the acoustical performance of the system, regardless of how personally satisfying you may find it.

So, we know you have beliefs that are inconsistent to the physics of the issue (in addition to the confusion of treatment types as being identical simply because they both employ porous absorption as PART of their constitution). Do as you like. But kindly cease to confuse and substitute your personal believes with that of objectively verifiable physics behavior.


And meanwhile we have another who hallucinates that we only advocate acoustical treatment who has failed to read the post to which we responded for meaning, as the post to which we replied specifically addresses the viability of the use of acoustical treatment that is insufficient to the task. Yawn.

That was my question to Local. And you now . Is he an expert in your view that can be trusted?


You first . Do you agree with his precondition of an excellent speaker giving you that choice? Or do you believe in taking his statement out of context and applying it to all speakers?


If said user claims to believe in Dr. Tool's teachings, they need to also believe in the sentence just prior to it. Is this a tough pill to swallow? That the story starts with a good speaker and not acoustic treatment?

toole is NOT "stuck on acoustic treatment" by any means. why have you suddenly turned against toole's commentary?


toole does not have any contention with that - and says the devices (treatments) commonly used by "acouticians".

have you seen the Harman room ??? loaded with broadband absorbers and diffusers!

actually, if we were using the non-ideal speaker (non-excellent speaker), then you have NEW issues since the off axis response is NOT uniform - thus you then NEED treatment to address! one doesnt NEED an ideal speaker to choose whether they want to absorb a high-gain early indirect reflection to "making the experience more intimate, and the imaging tighter and more precise." - as stated by toole.



ideal speaker + ideal room. how many here have both?
does the OP?


ideal speakers + ideal room? yes or no?

Ah, the cult of Toole.

So quaint and so limited.

Unfortunately, the substantial lack of awareness of MANY other significant acoustical experts is also rather apparent. Especially considering that Toole's ideas are not new and have been around for over 20+ years now.

Toole has some interesting and pertinent ideas, ironically with quite a few that the cult of personality with their adept selective attention go to great lengths to ignore. All of which makes using Toole's own quotes to illustrate these concepts so much fun.

And as local so adeptly points out, Toole's actual concepts have only limited applicability here, as few here have either the prescribed ideal power response speakers or the TREATED room required by Toole to complement the ideal power response speakers.

While an interesting concept, the concept is superfluous to the situation of the masses here with regards to their REAL speakers and rooms. I wonder, does Toole also have any eminently useful suggestions for how the folks here can improve the performance of their hydrogen powered cars as well?

Thus, they require the alternative approaches which amazingly enough are either similar, if not identical, to those prescribed by quite a few others for the treatment of speaker room interaction for sources and bounded spaces that are not "ideal" - meaning just about EVERYONE here.

But if anyone happens to find themselves on the planet Uranus with IDEAL POWER RESPONSE speakers AND an appropriately TREATED room, AND they PREFER a loosely defined fuzzy but 'large' image in a MULTI-CHANNEL setting acceptable (as he himself notes its limitations in a 2 channel stereo environment), you can certainly follow Toole's survey driven approach.

Toole? Not at all. As you say, he has a systematic approach is broad and comprehensive. I am talking about you and Dragon. I am not hearing you talk about any other solutions here.


So?

does the OP have the "ideal speaker" and "ideal room"? yes or no. go back and re-read the original post if you have to.

and that's funny, because we are discussing ACTUAL solutions here BESIDES telling the user to simply go and buy new speakers and build an ideal room from scratch. how is THAT reasonable?

Actually, I dont believe the Perf-Sorber product has an embedded membrane (I think only the Q-Sorber product does). And further I don't believe it's performance is as broadband as 4" of fiberglass plus 4" of wall gap. So even though it's an engineered product I think it is still a good example of treatment that does not follow what has been discussed here.

I have experimented with treating early reflections in my own room with 1", 2", and 3" of acoustic cotton. It's completely obvious to me from listening that 2" is better than no treatment at all. I think that's relevant to the discussion even if you think it's not.

I didn't realize Dr. Toole teaches about ideal speakers and ideal rooms. These two things don't exist in real life and I am pretty confident he teaches things that do.


I don't know. That answer can be given only with measurements and you didn't ask him that and proceeded to suggest running ETC to analyze the room -- something Dr. Toole does not recommend at all. Hence my repeated question of whether you are a supporter of Dr. Toole's teachings. I don't understand why it is so hard to get this question answered. Would you like us to assume the answer on your behalf?


No one is telling him to go buy anything. You are not even addressing him anymore but the rest of us. On that front, I am asking if you believe in the full context of what you quoted. Why is this question difficult to answer?

As to what "ACTUAL" things he needs to do, it starts with addressing the area where the room has the most impact. Do you know which area that is?

Perf-sorber is a HYBRID product combining both absorption and diffusion whose effective performance limit is seriously curtailed below ~500 Hz.
Another example of such a hybrid product is a BAD panel mounted on a porous substrate, but whose low frequency effectiveness is further augmented by use of a 4" porous substrate.

Ironically, I have also previously suggested exactly such a topology as a viable alternative to purely porous treatment.


...So a request and an observation.

First, if you are going to attempt to debate objective topologies and behavior, please first perform the due diligence sufficient to even know what it is that you are trotting out as allegedly invalidating the concept I have actually mentioned.

Secondly, believe what you want. I don't care. You can crawl around on all fours so as to be careful not to get too close to the edge and fall of the earth if you like if that is your belief. Have fun.

But just once, if you want to debate objective performance, PLEASE get valid objectively determined performance data that is applicable to the situation at hand and that accurately relates to the stated application.



And now another fails to note the distinction between typical speakers that constitute ~99% of the market that feature a non-uniform collapsing polar response and the very few ('ideal' in Toole's universe) speakers that do feature a non-horizontally restricted uniform power response sufficient to provide a wide dispersion for which the prescription.

Its quaint how one runs for semantic games when the fundamental behavioral distinctions and their implications in Toole world are noted and the spotlight shown on them, rendering much of the utopian vision facilitated by the alternatives few possess a moot issue for the vast majority here.

So, it is not effectively broadband according to your definition right? (Its not clear to me if you are saying the diffusion performance is seriously curtailed below ~500Hz or if both absorption and diffusion performance are seriously curtailed below ~500Hz, but I suspect the latter since I doubt the diffusion is effective down to ~500Hz)

In that case my original point is still hanging out there unanswered - here is an example of a product that is recommended and used by a highly respected design firm for early reflection treatments that is not broadband. Does the fact that it is partially diffusive negate the requirement for it to be broadband?

This is only one example, and I only use it for illustration because its relevant to me - it is possible that other treatments that are not broadband are widely used for early reflections with highly satisfying (and perhaps objectively improved) results. Maybe not perfect/optimal/ideal results - but who has the perfect system to go along with the perfect room anyways?

I have and been in it in person multiple times. Have you?


Loaded? No. It is designed to simulate a normal living room. From the AES paper by Sean Olive:

"For this reason, the Harman International reference listening
room was used for these experiments [20]. The internal
dimensions of the room are: 6.4 m (w) x 7.32 m (l) x
2.74 m (h). The acoustical treatment of the room
consists of a combination of broadband absorption, and
reflective and diffusive surfaces. In its standard
configuration, the room has a relatively constant RT60 of
0.4 s (± 0.05 s) between 125 Hz - 4 kHz. This is a
typical value for domestic rooms based on a large
survey of homes done by Bradley [21]. "

Remember, an empty room is not anything anyone recommends to be used as is. As Dr. Toole would say, you need to "furnish" it to be similar to our typical listening rooms as they have. Put another way, imagine your typical living room having all of that acoustic material! If that is "loaded," then we better not load it up anymore .

I know... NOW.


I'm not using rigid fiberglass. It's more of a pink fluffy. 0.75 at 125 acoustic batts from the local hardware store.




This will be something I will do some homework on.



I was afraid the landlord might flip out about me hanging my acoustic panels from the ceiling. I don't think he would appreciate me rearranging the walls!

The fallacy shown above in the context of this thread is the idea that the only thing that we hear are the things that loudspeaker designers measure when they build speakers. While the speaker designers do a good job of measuring the most important things that we hear, they don't measure everything that affects our perception of sound quality.

Speaker designers don't as a rule design their loudspeakers to sound best in the worst rooms. Yet, based on years of observations of AVS forum posters, people often put good equipment in bad rooms.

The above post seems to have fallen into a logical hole of trying to prove that room acoustics don't matter very much over much of the audible range in any room by looking at the performance of speakers in rooms that were built by speaker designers to flatter their wares.

if they wanted to simulate a typical living room, why not make it look like a typical living room with bookcases and chairs and furniture, paintings, photos, etc.

to me, it looks like a professionally designed/professionally treated room and is using mathematical diffusers based on primitive root number theory, NOT simply bookcases. and they are also covering large amounts of surface area with broadband absorption - not something you will find in typical living rooms.


comparing a typical living room to that professionally designed and professionally treated harman listening room is most certainly NOT apples to apples. even the listening location is prime in the harman room, and the seating location will generally be constrained in a typical living room due to furniture arrangement.

the harman room is most certainly "loaded" with treatment. PRD diffusers, Poly diffusers, thick porous broadband absorbers --- covering a large amount of surface area within the room. what living room looks like THAT? why is it OK for harman (and yourself, as you've posted photos of your company's "reference room" and it has many diffusers) to use treatment in their professional room, but it is NOT ok for people here to use the same types of treatment in their dedicated room or typical living room?

what makes a typical listening room different such that one is NOT allowed to utilize the very types of treatment that you and harman use in their rooms? why do you feel the entitlement that it is YOUR choice as to what people put in their rooms?

see fotto's thread here -
http://www.avsforum.com/avs-vb/showthread.php?t=1374014

Well, maybe others have "no idea" what is going on. But people who measure and perform extensive double blind testing have concluded otherwise. This, from Dr. Tool's:


I am surprised folks are not aware of their well-known research in this area. I suggest reading this AES paper if you are still not convinced: http://www.aes.org/e-lib/browse.cfm?elib=12847

A Multiple Regression Model for Predicting Loudspeaker Preference Using Objective Measurements: Part II - Development of the Model
Author: Olive, Sean E.
Affiliation: Harman International Industries, Inc., Northridge, CA

"A new model is presented that accurately predicts listener preference ratings of loudspeakers based on anechoic measurements. The model was tested using 70 different loudspeakers evaluated in 19 different listening tests. Its performance was compared to 2 models based on in-room measurements with 1/3-octave and 1/20-octave resolution, and 2 models based on sound power measurements, including the Consumers Union (CU) model, tested in Part One. The correlations between predicted and measured preference ratings were: 1.0 (our model), 0.91 (inroom, 1/20th-octave), 0.87 (sound power model), 0.75 (in-room, 1/3-octave), and - 0.22 (CU model). Models based on sound power are less accurate because they ignore the qualities of the perceptually important direct and early reflected sounds. The premise of the CU model is that the sound power response of the loudspeaker should be flat, which we show is negatively correlated with preference rating. It is also based on 1/3-octave measurements that are shown to produce less accurate predictions of sound quality."

Now, this doesn't mean that listening tests are not used in development of speakers. They are and heavily so. But the design criteria for good directivity and smooth frequency response is heavily supported by the above research and listening tests.


I sure hope this is not an all or nothing proposition. If it is, then we better throw our all measurements. I hope that is not what you are saying. Because measurements are repeatable and objective. We better figure out how to put them to good use, rather than relying on some guy sitting in room tweaking the sound until *he* likes it and then proceeds to sell us speakers because "we don't know how to measure what we hear."


Worse case? Who talked about worst case? They are designing them for the typical home listening environment as I showed in the quote from Harman regarding their listening room.


The *fallacy* is to assume just because a room doesn't have nerdy acoustical treatment, it is a "bad room." From Dr. Toole


It is high time that we stop automatically making people feel guilty because they did not stick treatment in their living spaces.


What Dr. Toole and harman say in this regard, is backed by extensive data from their own double blind tests and measurements to work done by others. Lack of knowledge in that regard doesn't equate to them being wrong. To prove them wrong, you need to show your own data contradicting theirs. I see none of that in your post other than putting forward more folklore and "forum conventional wisdom." Please excuse me if I believe research done by experts in the industry than what a few folks think here .

Please let me see if I have this right. You don't want to believe what they have said in their published AES report and instead, rather speculate what might be? If I told you I had steak for lunch, you are going to ignore than and look for signs that I ate something else?

If you want to speculate, I would go in these two directions:

1. They did it because if they didn't, folks like you won't take their work seriously. If you go to their double blind listening test room, they have a diffuser on the ceiling. They will immediately tell you that it does absolutely nothing but they put it there to make people happy that there is acoustic treatment there.

2. The room is reconfigurable. Most of the treatment is on french cleats so that it can be changed or moved. Since they do extensive work there including audio for cars, they may have a need to try different alternatives.

But again, what they say about the room is clear. If they believed in what you say, the room will look like this:



It clearly looks nothing like this studio which you put forward as an example of a room done right. This one is *loaded* with diffusers.


The room is professionally designed based on their teachings as every empty room should. Your statement was that it was "loaded" with acoustic treatment as if to set it way apart from a living room and their statement clearly contradicts that. Remember, an empty room must have treatment. But that is not the topic of this thread.


You brought this room into the conversation and now complain it is not apple vs apple comparison? As I have said repeatedly, they believe as I do that if you have an empty room, you better treat it and know what you are doing to boot. So the fact that it is professionally designed simply confirms the same.


You are looking at a visualization through a perspective. You need to go and see it in person.


People can and must have it in their "dedicated room." I have said this countless times in my posts. The typical living room is not bare and already has treatment in it. The fact that the treatment doesn't look geeky doesn't mean it is not doing anything. It may not be perfect but if you get a good speaker designed to perform well there, then you are most of the way there. The next thing to focus then is not that area but low frequencies where no room, dedicated or otherwise, typically does well. The solution there does NOT start with room treatment but rather, attempting to remove the problem by other techniques.


You are allowed to do what you want. What is relevant is whether what you recommend is backed by science and research, rather than folklore and myth. The research points to low frequencies is the main area that the room impacts, not the high frequencies that people argue about to death. Get that right, and you may be surprised that the higher frequencies all of a sudden sound right too without doing anything to them! More on this later .

Straw man/deceptive argument, because I never said that Toole had "no idea" of what is going on.


Contrary to what one might deduce from your post's incessant reliance on the writings of Floyd Toole, as good as he is, he's not the only guy who has any valuable insights into speakers and speaker/room interfacing. Furthermore, having a different viewpoint does not remove one from the face of the earth, or even just the realms of people with something relevant to say on the topic.

The number of possible and relevant theoretical analysis, measurements, and DBTs approaches infinity and can be reasonably expected to continue for some years, even decades. Since Toole is just one man, it is unlikely that he will do it all.

Therefore the fact that Toole says or does anything is not instantly validated as being the sole relevant truth in any particular topic, and respectfully disagreeing or going beyond his developments is clearly quite possible.

Well, you quoted it and started your response with "fallacy" when I was showing their data and their research. That points to them getting the fundamentals wrong. That equates to no idea. But if you didn't mean it that harshly, no harm is done .


"Straw man/deceptive argument, because I never said that Toole is the only one how knows what is going on."


"Straw man/deceptive argument, because I never said that having a different opinion removes you from face of the earth."


"Straw man/deceptive argument, because I never said that Tool will do it all."


"Straw man/deceptive argument, because I never said what Toole says is instantly validated."

As I said, you are welcome to counter what their research with your own. Seeing how this is a second post devoid of such data, I trust their position stands regarding impact of the room on speakers and predictability of what we like relative to speaker+room performance. If you don't believe me, maybe you can explain why the people arguing with me such as Localhost, are also quoting Dr. Toole. Seems like if we have one thing in common, it is his teachings!

Agreed, which is why I was careful to add "in sight" rather than just say no traps. But in my experience, the vast majority of people who consider themselves audiophiles or otherwise serious listeners have no acoustic treatment at all. At least one Stereophile reviewer brags about his lack of room treatment. Of course, he has an extensive array of expensive wires and "power cleansing" products.


Exactly. And again, in my experience there usually is not something going on behind the scenes, though there could be and sometimes is.

--Ethan

that was NOT presented as an example of a room "done right" - i presented that photo as an example of a diffuser (read: treatment) that is effective across the entire broadband specular region - exactly like toole states that if applying treatment, then it must not modify the spectral content of the reflection like thin porous absorption or a shallow diffuser would. say what i mean, and mean what i say -

tell me - has toole done any listening test in the Ambechoic Blackbird Studio C? because the room is effectively anechoic (first reflection is -30dB down and rate of decay is linear to schroeder integral). curious to see what his findings would be, especially as the room is designed as a surround sound control/mixing room. george massenberg had this to say:


but hey, who is george massenberg and why should we "trust his ears".

but i don't really understand your attempt to steer my commentary away from what i said. the photo was an example of a proper broadband diffuser that would NOT alter the spectral content of the reflection as toole himself states in his paper.


but it IS "loaded" with acoustic treatment! on every surface/boundary! all of those poly diffusers, PRD diffusers, and broadband absorption panels ARE set way apart from a typical living room! are you comparing the performance at scattering of a typical living room bookcase vs that of the RPG PRD diffusers in the harman room that offer a flat power response? what "typical living room" has THAT much thick broadband absorption on so many boundaries? that harman room configuration looks like a padded-cell that AJ constantly refers to. if anything, typical living rooms have thin carpet which is NOT a broadband absorber, and then flat, reflective walls and ceilings.




so what exactly is it that you have an issue with if people want to add 'treatment' into their dedicated listening space or living room? you and AJ seem to be the primary opponents to treatment. why is it OK for harman room or your company's reference room to apply diffusers instead of bookcases, but typical living rooms or the OP's room it suddenly meets contention.

what do you have against people wanting to apply treatment in their rooms? who are YOU to decide?



glad we're finally on the same page. your conclusions differ from AJ as he does not ever see the need for 'treatment'. im curious why you find such contention with ME when apparently you are now in agreeance with myself and toole - when i never see you argue or discuss with AJ on his stance of NO treatment ever.

i presented toole's commentary to support my statements in this thread. are you still contesting mine or toole's commentary?

The room is at USC's Viterbi. It appears to have been built by a grant from NSF since they named it after it. Here is more on it: http://www.audioholics.com/education...yssey-dsx-10.2

"we went to USC, where the days first demonstration began at USC in the Viterbi School of Engineering building. This houses the Immersive Audio Laboratory, part of the National Science Foundations integrated Media Systems Center (IMSC). This is a multi-million dollar multimedia room, the quietest room in all of the USC campus.... IMSC has 28 faculty members, more than 250 research assistants, and a annual operating budget of nearly 10 Million dollars. In reference to the work done at the Immersive Audio Laboratory, "The group here works at the intersection of acoustics, psychoacoustics, and signal processing.... This room was clearly designed by acoustics experts for exactly this purpose, multimedia and multichannel sound experiments. "


And per research I showed, there is no requirement that they do either. Doing otherwise is looking at food and deciding it needs salt .


Well, we should get data before we decide. It took me 10 seconds to get to the above article where the earlier quote came from. Clearly the room was not akin to the other examples you used.

So you are saying it is not an example of a room done right?


Where do you find in Dr. Toole's teachings that back wall behind the speakers should be diffused as seen in the picture?


I don't know if he has or hs not. For that matter, I don't know what he had for lunch yesterday either . Regardless, as I post here, http://larchive.avsforum.com/www.avs...php?p=21851266, the term "Ambechoic" is a marketing term coined by RPG. And they plan to produce their own objective and subjective data: "Future Research: We are beginning both objective and subjective measurements on the space...." If you have that data, we can examine it. Until then, it is a wonderful looking space, in need of objective data to analyze it .


George is a good man. I appreciate and accept his feedback that the room performs as he expected it. It doesn't mean I rush and put 3 foot sticks on my front walls though . Here is what he says there:

"the prime number which determined the primitive root diffusor calculation was suggested by Peter DAntonio (my collaborator in the project) was is 138,647, yielding co-primes of 181 & 766. this linear series was folded into 2D by the Chinese Remainder Theorem. there is roughly 47 tons on the walls after milling on a Cosmac horizontal mill, which ran for about 3 months cutting 1532 pieces of 1" MDF. we had thought that "sagging" might be a problem, and worked out a system of installing 1/4" dowels at strategic spots in the array to support it should this be the case - it hasn't been a problem, though."




We should certainly respect his opinion (his last name by the way is spelled Massenburg). He certainly has earned that. If you feel his opinion applies to your living room, by all means, go and buy tons of material and CNC them to fit your walls .


The picture was used as an example of what "loaded" meant. Since you say the same then it was appropriate use .


I have said a dozen times that dedicated spaces need treatment. I don't understand how you could be so confused about my position there. Would you please confirm you have read this response so that we don't rehash it another time?

As for living rooms, I have conveyed Dr. Toole's research saying it is not an issue of concern. You have put forward no contrary data. Does your living room have treatment? If so, what is it and do you have measurements of it? Can you demonstrate its efficacy in an objective way as he has done?


Your beef needs to be with Dr. Toole and his research, not us. We are just messengers. On one hand, you quote Dr. Toole, on the other you resist his other statements with regards to living room treatment. If you sit and listen to him in person, you see that he is even more vocal about people running off to copy what they see in recording studios. He shows you pictures of his own living room which looks nothing like the dedicated spaces you have been posting.


Well, neither you, nor I are deciding. That is for the OP . What we are doing is putting forward data. On my side, I quote top experts, provide links to authoritative research papers on AES site, together with my interpretation of them, having spent time with these researchers, participated in tests that formed their opinion, etc. That enables me to summarize their findings in ways that I think make sense, are logical, and pretty easy to understand and follow.

You have likewise put forward your opinion and that is cool. Op will have to decide who is more convincing.


I don't know why it is important to argue about AJ in this thread. He is not here and what we have to do to treat our rooms is immaterial to that point.

You on the other hand are here and my arguments with you is that you never share first hand data, and what you post, appears to be copies of other people's forum posts (mostly from Pro forums with different requirements). Even when referring to writings of Dr. Toole, you again show snippets posted on forums. I am worried that you have only grabbed fragments of what he talks about and don't know the totality of it. Hence the reason you can't agree when more of it is stated.

I am especially concerned that you never share any data that you have created yourself, nor any personal experience you have with these products, measurements, etc. These all point to someone who is what I call a "forum summarizer" and not a proper source of research. I apologize if this is not you but you asked why, and I share my impression .

For all of AJ's ills, he has built his own speakers and spent a lot of time measuring and listening. And he has shared that information. Until you catch up to him, I am afraid I can't rely on your statements which are cut and pastes from forums as opposed to authoritative research. I hope you understand .


As I noted, you do not convey Dr. Toole's teaching with completeness and proper point of view. When I provide the full context, you no longer agree with him. In that regard, I don't see you in agreement with him in any meaningful and logical way. Or else, we would be done by now arguing over whether living rooms need treatment or not.

i haven't said anything about the room as a whole / example of "a room done right" - im talking about the specific types of treatment and what toole says about them.

a thin porous absorber or a shallow diffuser DOES alter the spectral content of the reflection, as such treatments are not broadband to the entire specular region. exactly what toole says NOT to do.



not relevant to the conversation. the photo was an example of a diffuser that has sufficient bandwidth (vs shallow diffusers or thin porous absorbers). the context was on effective treatment, not whatever you are effectively trying to "steer it" into being.




yep - it's a room model. just like NER, LEDE, RFZ, etc - only it is prominently a surround sound room model.
and a control room/mastering room model at that - which means, the direct signal from the source needs to be ACCURATE such that the room is NOT imposing or masking its sound on top of what is "heard" at the listening position - such that the mixing/mastering decisions made are TRANSFERABLE to other rooms and systems. a control room needs to be as accurate and neutral as possible for precisely such reasons. and guess what, some people subjectively prefer this "accuracy"!


it's more "subjective preference" feedback to add to the conversation - who doesn't want more of that, especially from industrial experts. and especially since the room is effectively anechoic and ACCURATE, and he seems to think quite highly of it !!



i appreciate the strawman - but i never said anyone should go out and do that. i did, however, use Blackbirds diffuser (PRD) as an example of a diffuser that is of sufficient bandwidth - as the context of the conversation was with regards to 'treatments' that are NOT supposed to alter the spectral content of the reflection as stated and published by toole.



you are the one who is going against toole's commentary - toole explicitly states:


sounds like toole gives us the OK to decide what to do with early reflections based on our own tastes!! NOT for amirm to decide.

I thought you said: "but hey, who is george massenberg and why should we "trust his ears." You asked us if we trust his ears but you yourself don't? You have less conviction about your evidence than I do .


I didn't ask why the diffuser isn't thin. I asked what Dr. Toole advises for the back wall treatment. Do you know it and can explain why? I think this question was asked earlier in this thread so the answer is quite relevant.


As I said, it is a *marketing* term. Not a scientific one. To wit, I just searched for it on Audio Engineering Society web site. This is what I get:

Showing results for Anechoic site:aes.org
No results found for Ambechoic site:aes.org

If it is a room model, how come there are no published papers on it as there are for other models or even a reference to it?


Ask two recording engineers how a room should be treated and you may get three different answers. Accuracy has specific requirements, one of which is frequency response. We don't have that data. Without it, there is no way I will accept that sound as being accurate. It might be, but we lack data to draw conclusions. What we do have is a pretty picture so it is not surprising that you are biased that way. You wouldn't be the first one to like what your eyes say, rather than your ear .


This point has been accepted repeatedly by me. Why do you keep mentioning it? It gains you no point in regards to following Dr. Toole when you scuff at just about anything else he has to say.


Actually no. You took out key part of that paragraph as I corrected you earlier:

Do you agree with the part in red or prefer to accept one sentence and not the other?


No, what it sounds like, pun intended, is that you need to start with the speaker if you care about its high frequency response. Do you believe that?

Are you suggesting that Toole is saying that unless you own a Harman speaker, properly placed broadband absorption will be of no benefit?

What is "properly placed" broadband absorption?

Amir;
There are a few of us in SE Michigan area (fotto is N.E. Ohio might drive up?) who want to go to this room.
Please PM me details on contact info.