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Does sound sounds better in a room full of furniture and stuff or without ? - Page 26

post #751 of 871
The irony is that the domain map provides exactly such a means to document that and to proceed with an actionable plan! - even for someone such as himself who has no direct knowledge of the subject.!
post #752 of 871
yes, i'm looking forward to his "overnight expert" commentary re: Analytic and domain-map after he spends some time with google...
post #753 of 871
Oh, it will most probably be from one or three easily locatable sources on the web. And then he will be confused by the dates posted....

But seeing as they will be from sources he has already 'discredited'.... rolleyes.gifrolleyes.gifrolleyes.gifbiggrin.gifbiggrin.gif
Edited by dragonfyr - 7/29/12 at 3:25pm
post #754 of 871
Quote:
Originally Posted by dragonfyr View Post

The Energy Time Curve as it was originally referred has indeed been changed to the Envelope Time Curve. And at least several of the people you selectively quote- erroneously thinking that they have in any way invalidated the use of the ETC - agree.
Invalidate? You can't stay with your own argument? You were fighting over use of words. You claimed the right term was envelop and not energy. And that I was using the wrong term. I showed that everyone else including your own experts you listed (Don Davis) were using the "wrong" term and so were you. But that I was the one using it the way you said I should have. You can't get things more backward than that.
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But then, again you have no idea as to exactly WHAT the ETC shows!
It matters not in this context as I quoted *you* saying all of this and agreeing vehemently with Dr. Toole. Here it is again:
Quote:
Originally Posted by dragonfyr View Post

[From Dr. Toole's book] The message is that we need to know the spectrum level of reflections to be able to gauge their relative audible effects. This can be done using time-domain representations, like ETC or impulse responses, but it must be done using a method that equates the spectra in all of the spikes in the display, such as bandpass filtering. Examining the “slices” of a waterfall would also be to the point, as would performing FFTs on individual reflections isolated by time windowing of an impulse response. Such processes need to be done with care because of the trade-off between time and frequency resolution, as explained in Section 13.5. It is quite possible to generate meaningless data. All of this is especially relevant in room acoustics because acoustical materials, absorbers, and diffusers routinely modify the spectra of reflected sounds. Whenever the direct and reflected sounds have different spectra, simple broadband ETCs or impulse responses are not trustworthy indicators of audible effects". p. 93

DUH!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!rolleyes.gifrolleyes.gifrolleyes.gif If you need a text to explain this to you, the book won't help! It's too late! ... Combine that with the fact that existing treatments may indeed effectively EQ the incident energy and act as equalization, effecting some frequencies more than others.

Thus if one uses live material as a stimulus that may feature varying spectral content at differing times of the program, and you have boundaries or boundary treatments that do not behave in a broadband manner and may indeed effectively EQ the incident and reflected energy, you may indeed end up with whacked data. And anyone who conducts a test in such a manner is an idiot.

Best practices require that we evaluate the behavior of the boundaries and /or treatments specifically to ascertain their behavior over the full specular spectrum. Such boundaries that do not exhibit such a broadband response should be corrected. ... Of course boundaries that are not broadband and which do not function in a linear fashion will effectively EQ the incident energy! And attempting to compare unlike stimuli which by definition consist of non-equivalent energy content, is so whacked as to render the label of a “mistake” an understatement!!!

As the tool can be used for a near limitless array of applications, (including a plethora of well designed variations) with regards to boundary investigations a simple rule of thumb implies that one:
1.) Ascertain the spectral nature of the boundaries followed by the behavior of any existing treatments. This will most probably require that one remove any treatments and first establish a baseline of performance for the boundaries.
2.) Once this is established and any lack of uniform broadband behavior rectified, insure that any treatments employed (assuming they are necessary and perform the desired function) are also broadband.
And except for the purposes of selectively ascertaining degrees of deficiency, identical broadband sweeps should generally be used for testing, with any tests intended to be directly compared conducted with equivalent stimuli under equivalent conditions. And if broadband sweeps are not employed, care MUST be exercised in comparing any results generated by dissimilar stimuli! Depending upon the nature of the behavior to be examined, sweeps maybe be bandwidth limited in a narrow fashion, realizing the reduction in resolution, or 'bandwidth limited' in the broadband, increasing the resulting resolution and generally employed..

So if these are so obvious as to not need anyone reading a book, how come in case after case you and Local are ignoring the same principals? Take any of these examples and show how best practices were followed as to avoid "whacked data" even though posters had rooms that were full of products and furnishings that color the reflections and hence produce invalid amplitude. Here is the list of cases where Local recommended ETC: http://www.avsforum.com/t/1413173/does-sound-sounds-better-in-a-room-full-of-furniture-and-stuff-or-without/510#post_22223617. How did they not violate #1 and #2? Have you fallen out of agreement with your own statements?
post #755 of 871
Blah blah blah. And the Big Lie continues.

Just how many fools can you fit in that clown car of yours?

Toole's case that you originally cite employs a flawed process.

We don't have the problem.

It is YOUR problem to figure out why YOU do and why , like a fool, you persist in clinging to it. I would suggest correcting your mistaken process before using your "ETC meter".

But if you continue with YOUR flawed process, yes, I would suggest using bandwidth limited ETCs and correlating the levels between dissimilar bandpasses. It can be done, but its the hard way to go - a process performed by those unaware of how to avoid the additional complexity (or in limited cases by those who do know for cases of exceptional local analytical investigation). The irony is that such a convoluted and unnecessarily overly complex method can indeed work, provided the compensation is performed.

And ironically that method DOES work just fine for masochists who fancy such a predilection, contrary to your FALSE assertion.
Edited by dragonfyr - 7/29/12 at 6:01pm
post #756 of 871
Amir is still trying to catch people in wording slipups as a form of discrediting a comprehensive process using the full capabilities of many useful tools. I'm still not sure exactly why. Especially strange considering his reference showroom was designed using these tools.

What is more notable is that he still isn't able to offer an alternative, not even in the barest outline form, unless you take audiophilesavant's mockery seriously. The closest he comes is "make your room look like one of toole's sketches".

This is surely a hollow salvation he offers.
post #757 of 871
Quote:
Originally Posted by Bigus View Post

Amir is still trying to catch people in wording slipups as a form of discrediting a comprehensive process using the full capabilities of many useful tools.

I think that this is a byproduct of Amir's debating methodology. The first thing he does is try to fit whatever he reads into the knowledge he has acquired up until this time. Trouble is, unlike the world class authorities he favorably compares himself to like Toole, that knowledge base has some fundamental problems, such as his adherence to and conformance with many of the well-known audiophile myths.
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I'm still not sure exactly why.

A means for at least to himself, maintaining some influence over, but preferably control of the situation.
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Especially strange considering his reference showroom was designed using these tools.

I suspect that the key here is in his statement of his relationship with the organization in question: "Founder". I think you can take that to mean "Found and left in the hands of others".
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What is more notable is that he still isn't able to offer an alternative, not even in the barest outline form, unless you take audiophilesavant's mockery seriously.

I believe that the universal alternative is "Trust Me".
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The closest he comes is "make your room look like one of toole's sketches".

I'm not sure that Toole sketched every possible room. In fact I'm sure he didn't. That leaves us on our own. ;-)
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This is surely a hollow salvation he offers.

Agreed.
post #758 of 871
There's one thing for sure that this thread confirms. Don't trust a salesman!

It's sad that vendors are flooding the acoustics forums with their often misguided information. Don't get me wrong. I'm not saying that aren't helping people to improve their rooms. Of course, treatment over no treatment will almost always do some improvement. But there are better ways to treat a room that will give superiour results and often also cheaper. I don't know if it's mainly due to lack of knowledge or if the vendors aren't simply telling the truth because they would sell less products. And not to mention that many of their products wouldn't sell very good if people had the kowledge about the importance of broadband treatment. Many of their products are simply too thin for broadband results and will alter the spectral content.

So be careful people from where you get your advices from. One can easily be lead down the wrong path. I've been there myself.
post #759 of 871
Quote:
Originally Posted by omholt View Post

There's one thing for sure that this thread confirms. Don't trust a salesman!
It's sad that vendors are flooding the acoustics forums with their often misguided information. Don't get me wrong. I'm not saying that aren't helping people to improve their rooms. Of course, treatment over no treatment will almost always do some improvement. But there are better ways to treat a room that will give superiour results and often also cheaper. I don't know if it's mainly due to lack of knowledge or if the vendors aren't simply telling the truth because they would sell less products. And not to mention that many of their products wouldn't sell very good if people had the kowledge about the importance of broadband treatment. Many of their products are simply too thin for broadband results and will alter the spectral content.
So be careful people from where you get your advices from. One can easily be lead down the wrong path. I've been there myself.

I agree with your facts, but my concern is that people see so many situations where people are duking it out, and just sit back and do nothing for themselves.

As you say, "treatment over no treatment will almost always do some improvement."

I also agree with your concerns about to-thin products and vendors who beat their own drum and try to punch holes in everybody else's.
post #760 of 871
I meant to answer this earlier but keep forgetting:
Quote:
Originally Posted by fotto View Post

So what happened to all the "Stars" of the thread.....seems like the shows over and everyone is just waxing philosophic at this point smile.gif Maybe it's just a case of audio burn out.
I can't speak for others but those were not my reasons. I went to see if I could get one of the experts mentioned in this thread and get him to respond. He took one look at the thread and came back with a page full of negative comments on why anyone would want to engage in this kind of rude discourse. And that nothing good comes out whatsoever. It could not have been a more negative response. He then asked me why I bother doing it. I explained that for every vocal poster there are 20 who only read. And that it is that group that I write for, not the select few who are posting the way they do. To test the theory, I figured I stop posting for a couple of days to see what happens. That resulted in people coming forward and having a good discussion proving the theory that all is not lost.

That said, he did have a very good point. Why would any expert want to come and subject themselves to the kind of name calling that goes on here?

Folks keep trying to read and understand the meaning of expert's writings as quoted. Yet in the next breath they stop any chances of those experts coming here and answering questions directly and clarifying what is being talked about. We can't say we are searching for knowledge but in the next breath explicitly or implicitly let the atmosphere become this bad.

I am fortunate enough to have access to these experts outside of the forum so I am not saying this for me. But for the rest of the community, why not take a harsher stance and report members who bring the conduct below that which encourages industry participation? Look around. Do you see that many people like Ethan and I who tolerate this kind of talk day in and day out? You can argue with the technical point being made but I hope you don't agree in favor of the unprofessional bickering that raises the noise floor and keeps away valuable expert participation.
post #761 of 871
Oh, the trials of being a pristine idyllic angel amongst the morass of loathsome barbarians...

...And he still thinks we were taking issue with Toole...despite intentionally quoting him as a source HOW many times?.....

How many times does one have to say that if, in a surround environment, you want a BIG sense of envelopment along with an equally BIG amorphously defined image, you may very well like the reflection rich environment. But if you wish a sense of envelopment along with a more accurate precisely defined image, then there are other alternative response models that are better suited.

And with regards to either approach, and the still others available, there are indeed objective means by which to evaluate the physical acoustical behavior as it relates to how the particular subjective psycho-acoustic responses are elicited.

So select the response you desire and from there one may proceed to evaluate the given space and then to modify it based upon an awareness of the actual existing behavior and with the desired physical and subsequently elicited psycho-acoustic response.

The fundamental difference between the 'two' camps? That's simple. We allow for an individual to actually possess and exercise their own preference.

The other allows for only one conclusion. And he has other's surveys to prove it lest you dare disagree!
Edited by dragonfyr - 7/31/12 at 1:20pm
post #762 of 871
Quote:
Originally Posted by dragonfyr View Post

...And he still things we were taking issue with Toole...despite intentionally quoting him as a source HOW many times?.....
How many times does one have to say that if, in a surround environment, you want a BIG sense of envelopment along with an equally BIG amorphously defined image, you may very well like the reflection rich environment.
You have this backward. Multi-channel already has that sense of envelopment in the recording. Side reflections do not contribute materially there and hence in that situation (i.e. multi-channel) is not important to leave them reflective. From Dr. Toole:

"Here it is again necessary to emphasize that reflections that occur in small rooms cannot alone generate a sense of true envelopment. Envelopment requires the strong sounds delayed by 80 ms or more that are in the multichannel programs and that are reproduced through suitably located surround loudspeakers. Additional room refl ections of those greatly delayed signals may enhance the impression, but the initial delay and the appropriate directions are provided by the recorded sound and delivered by playback loudspeakers."

We later see the effect of side reflections being higher as the number of channels is reduced:

"It was in this room that experience was gained in understanding the role of first reflections from the side walls. The drapes were on tracks, permitting them to easily be brought forward toward the listening area so listeners could compare impressions with natural and attenuated lateral refl ections (see Figures 4.10a and 8.8). In stereo listening, the effect would be considered by most as being subtle, but to the extent that there was a preference in terms of sound and imaging quality, the votes favored having the side walls left in a reflective state. In mono listening, the voting definitely favored having the side walls reflective."

Clearly he is talking about importance of leaving side reflections be in as few channels as mono. He goes to say:

"See the discussions in Chapter 8, and Figures 8.1 and 8.2, which show that attenuating firstrefl ections seriously compromises the diffusivity of the sound field and the sense of ASW/image broadening. One of the problems with both music and movies is that sounds that in real life occupy substantial space—multiple musicians or crowds of people, for example—end up being delivered through a single loudspeaker—a tiny, highly localizable source. The precision of the localization is the problem. Most of what we hear in movies and television is monophonic, delivered by the center channel, so a certain amount of locally added room sound may be benefi cial; this is defi nitely a case where a personal opinion is permitted."

So the benefit in multi-channel is that of widening what should have already been there (e.g. center dialog). It is improper to say it is the sense of envelopment as that per research cannot be induced by the room reflections.

There is no reading of the above that points to him recommending side reflections for multichannel and not stereo.
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But if you wish a sense of envelopment along with a more accurate precisely defined image, then there are other alternative response models that are better suited.
As we have discussed, that "wish" is only true if the person has experimented and knows it. I have asked you to share with us what you have wished and you have refused. As has Local. If you two can't figure that out, why are you asking others to do it? But sure, if someone thinks they are in that camp by all means put absorption. Just don't think there is a 50-50 chance that you might like it that way or worse yet, that you are already in that camp because you like the sound of words like "precisely defined image." You will likely vote the other way once you are put in a test facility asking you which you like better smile.gif.
Quote:
The fundamental difference between the 'two' camps? That's simple. We allow for an individual to actually possess and exercise their own preference. The other allows for only one conclusion. And he has other's surveys to prove it lest you dare disagree!
Not really. Both camps allow for a choice. It is a political spin to say otherwise. The real difference is that one camp leads with research of how we hear, the other puts out a tool that shows "whacked" data to use your terminology and waits for you to figure out which way the sun rises next smile.gif. You start with bad data and end with confusion. Worse yet, you never tell us if you have traveled this road. Ever!

Arny, are you still here? Do you think listening tests are surveys to be put down as he just did in favor of measurements?
post #763 of 871
Quote:
Originally Posted by amirm 
You have this backward. Multi-channel already has that sense of envelopment in the recording. Side reflections do not contribute materially there and hence in that situation (i.e. multi-channel) is not important to leave them reflective.
Interestingly, this does not coincide with sanjay's observations/preferences. This is a topic I brought up in another thread. Research here seems limited, and what is there seems to point to extensive diffusion as a potential goal. I'm not personally decided on the matter.
post #764 of 871
Quote:
Originally Posted by amirm 
To test the theory, I figured I stop posting for a couple of days to see what happens. That resulted in people coming forward and having a good discussion proving the theory that all is not lost.
Interesting observation.
post #765 of 871
And the BS continues.

Yup, until book report boy came along, NO ONE used their ears at all! Ever! In fact, it was all done in simulation with ear plugs!

In fact everyone's knowledge was limited to reading A book and subsequently appointing themselves an expert based upon what they read. Oh wait, I am describing another...

And he continues to display his abject ignorance. Oh, what would acoustics have done had not Toole come along and suggested actually using one's EARS?!?!?! Wait for it folks, in a post or two Toole will be credited with inventing EARS.

..."If I have traveled this road." rolleyes.gifrolleyes.gifrolleyes.gif

Book report boy, I have had more formal training and applied experience in a month than you have had in this area in your entire lifetime.

And he just keeps on shoveling... pure as the driven snow...such an angel!..
post #766 of 871
It took just a few minutes to go from:
Quote:
Originally Posted by dragonfyr View Post

...And he still things we were taking issue with Toole...

To:
Quote:
Originally Posted by dragonfyr View Post

And the BS continues.... Oh, what would acoustics have done had not Toole come along and suggested actually using one's EARS?!?!?! Wait for it folks, in a post or two Toole will be credited with inventing EARS.
Clearly you do have issues with what he has to say smile.gif.
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Book report boy, I have had more formal training and applied experience in a month than you have had in this area in your entire lifetime.
"Boy?" I have gone from you calling me Mr. Bob, an adult presumably, to a boy? smile.gif
post #767 of 871
Quote:
Originally Posted by amirm View Post

Clearly you do have issues with what he has to say

Go back and read it again, s l o w l y.

I have issues with what YOU say about what he says.

Just out of curiously, do you yourself have ANYTHING of substance to add regarding acoustics?

...And moving up in station from an animated paperclip to an animated figure presumably with arms facilitating word searches and cut and paste is quite an evolutionary leap......straight from the primordial ooze into the swamp of dictatorial arrogance..
Edited by dragonfyr - 7/31/12 at 1:24pm
post #768 of 871
Quote:
Originally Posted by dragonfyr View Post

I have issues with what YOU say about what he says.
Let's test that. He said in my last quote of him: " The precision of the localization is the problem. " Do you have issues with that or are in agreement?

Along the same line, are you in agreement with everything in his papers and his book? This is your chance to list the areas that you would dispute. Otherwise, the road from here will get even rockier smile.gif.
Quote:
Just out of curiously, do you yourself have ANYTHING of substance to add regarding acoustics? ...And moving up in station from an animated paperclip to an animated figure presumably with arms facilitating word searches and cut and paste is quite an evolutionary leap......straight from the primordial ooze into the swamp of dictatorial arrogance..
I suggest saving your curiosity there long enough for us to establish once and for all that you are in agreement or not with Dr. Toole. I am pretty sure he has contributed something of substance to the field of Acoustics.
post #769 of 871
No book report boy, I am NOT in agreement with EVERYTHING he says about ANYTHING. And I am in substantial disagreement with just about EVERYTHING you say.

I am sorry that you erroneously interpret generalizations to mean absolutes just as you absurdly do with your surveys that YOU insanely interpret to be conclusive and absolute.

The fact is that you are unable to acknowledge anything that deviates in any way from your absolutist position. And to that degree, you are a joke.

But we will watch and see just how long it takes for YOU (and not Toole, seeing as how you cannot even represent what you read correctly) to offer any display of actual acoustical insight that is not sourced from a word search or cut and past. ...as you are always good for a laugh...
post #770 of 871
Quote:
Originally Posted by dragonfyr View Post

No book report boy, I am NOT in agreement with EVERYTHING he says about ANYTHING.
So what are some of those areas where you disagree? Would use of ETC be one of them?
post #771 of 871
I have no wish to discuss ANYTHING with you. Let along your dictatorial misinterpretation of others work.
You are neither competent to interpret any issue in acoustics nor to act as arbiter of what Toole has written.

But it IS hilarious to watch as strut about pretending to be the arbiter and spokesperson for Toole, as if his book is not sufficient in itself.

Toole's Mini Me....I bet he's proud!rolleyes.gif

And the reflection rich response goes back to the introduction of the Bose 901 direct reflecting speakers. And the fundamental response issues remain the same. My how the ancients keep stealing all of your inventions...


.
Edited by dragonfyr - 7/31/12 at 2:59pm
post #772 of 871
still waiting on his google analysis of the domain-map and Analytic.

rolleyes.gif
post #773 of 871
r9TkZ.png

"optional areas: absorb, diffuse, reflect"

does toole recommend the "flutter echo solving" auralex t'fusors that amir sells from his company's show room?
post #774 of 871
Quote:
Originally Posted by dragonfyr View Post

... I have had more formal training and applied experience in a month ...

Can we please see some examples of the projects you've worked on ?

Cheers,
post #775 of 871
Oh ... and how about some info on your own theatre room ?

Cheers,
post #776 of 871
I mentioned at a another forum that Toole (or probably his followers to be accurate) has basically brought confusion. I believe this thread shows that exactly. But here the problem also lies in misinterpration of what Toole actually has conveyed.

Something worth mentioning when it comes to the so called favored Toole side-reflections are the following:
- It requires speakers with excellent polar respons. Most don't have that.

- Does Toole say at what time and gain they turn to be beneficial? The arrival in both time and gain are crucial. And from what I've heard from close peers to Toole, he never meant that very early sidewall reflections were something positive. More when they were arriving at late as perhaps 15 ms.

- The researches seem to be conducted in rooms with very little spaciousness. Would the outcome be different if the room was treated differently and especially with the spaciousness arriving form lateral diffusion?

- Absorption is not the only way to attenuate sidewall-reflections. There are other ways that will not only retain more energy, but actually attenuate reflections even more. It's been used for decades and is something Toole doesn't even seem to mention.

- Amir tries to make this black and white. The fact is however that Toole researches were not very conclusive. Whether sidewall reflections were experienced as pleasing or not dependent on the music material. It actually varied quite a bit. Not to mention that this was based on preferences and never accuracy. Here's Toole's own comments on this:
Quote:
"Hi Bert.

People who say I dismiss room reflections as unimportant - and there are a few, it seems - simply have not read or understood my book. It is patently obvious that room treatment is necessary, if only to establish conditions suitable for comfortable conversation. This requires reverberation times under 0.5 second. This alone, also pretty much ensures that film dialog will be clearly understood.

The most debated issue relates to first lateral reflections. Some of those arguing vociferously in favor of eliminating them seem to have a conflict of interest, being providers of acoustical materials. Others have more reasoned arguments. I say up front that there can be no universally satisfactory answer because there is no universal scheme for recording stereo or multichannel signals. Only through controlled listening tests can we get useful insights, and these are in short supply. In the meantime opinions reign supreme, and there are many of them.

In the book I show results of several double-blind evaluations, some done by me, some done by others, showing that listeners tend not to be disturbed by lateral reflections, and many even prefer them. I also point out that the professional side of the industry almost universally feels the need to eliminate them. I suggest, respectfully, that humans have a remarkable ability to learn, to adapt, and that recording engineers spending their days adding, adjusting, and removing - at will - delayed sounds from mixes undoubtedly are more highly sensitized to these sounds than are lay listeners. This probably applies to any audio professional, acoustical consultant or enthusiast who focuses enough attention on this task. We learn to hear things and, once heard, they tend not to go away. I well remember that during the resonance detection experiments, we all became extremely skilled at hearing and identifying resonances. During the tests, and for some time afterward, we were hearing little resonances in everyday life that normally would have been totally unnoticed. From such things paranoia is born, and if we had taken this to an extreme, we would have damped our wine glasses.

For stereo listening I have found that it very much depends on the program. Music with lots of decorrelated sounds, classical for example, is sometimes enhanced by reflections, although coincident-mic recordings may benefit from a lack of reflections - letting the direct sounds be more dominant (the Blumlien stereo effects work best in an almost anechoic situation). Pan-potted recordings (the majority of pop) end up delivering essentially monophonic sounds from left and right loudspeakers, and these may well benefit from a bit of spatial enhancement. Otherwise we are left with what really annoys me about stereo: a relatively spatial set of phantom images created by both loudspeakers, and two "anchor" images created by the left and right loudspeakers playing solo. In some recordings we hear a whole string section emerging from a single loudspeaker. Not realistic, and not even pleasant. In the past, I have recommended that serious stereo listeners hang absorbent drapes along each side wall, pulling them out and pushing them back to suit what they are listening to. Our listening room at the National Research Council in Canada had this feature.

In the book, I put more emphasis on multichannel audio, where much of the important sound is delivered by the center loudspeaker, farthest from the side walls. In these situations I conclude that treatment of the side wall reflections is an option. There may be situations in which their effects are audible, but when all 5 or 7 channels are operating, it is improbable that natural room reflections have much of an effect. Other things being equal, the effects of the room are most audible when only a single loudspeaker is operating, and it becomes less so as other loudspeakers (channels) contribute additional uncorrelated sounds.

Of course the degree to which reflections are activated depends on the directional properties of loudspeakers, and the extent to which the loudspeakers are well behaved in their far off-axis responses (side wall reflections can be 50 degrees and more off axis). It has become clear over the years that, with hard side walls, the more uniform the off axis frequency response, the higher the rating of the loudspeaker. So, one has to wonder whether at least some of the dissatisfaction with reflective side walls has to do the misbehaving loudspeakers. Sadly, most manufacturers don't provide us with sufficient data to judge. And that is another, and I would argue much more worthy topic, to argue about.

Best wishes,

Floyd"

So we see that whether side-wall reflections are something positive or not greatly depends on many factors. Music material, taste, speakers, time of arrival and gain in db, how the rest of the room has been treated etc.
The best way to find out is simply to try it out yourself. Most people who try dampening early reflections from sidewalls seem to favor it. I havent't seen many who don't. One need to make sure one does it broadband though. Or if the plan is to use diffusion in the rear of the room, one could redirect sidewall reflections instead of dampening. But this is certaintly something you would need to use ETC for. Besides waterfall, ETC is the most useful and important tool to treat small rooms with. Well known in serious acoustic circles for decades. Don't let someone try to persuade you differently.
post #777 of 871
Quote:
Originally Posted by Bigus View Post

Interesting observation.

The obvious meaning being that when he is quiet, everybody else learns.

This lines up with how much sage advice that almost all of us received and (hopefully) to some degree heeded over the years? ;-)

Stuff like:

"Learning is made more difficult by opening your mouth too much".
Edited by arnyk - 8/1/12 at 7:20am
post #778 of 871
Quote:
Originally Posted by omholt View Post

- Does Toole say at what time and gain they turn to be beneficial? The arrival in both time and gain are crucial. And from what I've heard from close peers to Toole, he never meant that very early sidewall reflections were something positive. More when they were arriving at late as perhaps 15 ms.

i've brought this up many times; a few here preaching the gospel continually represent some frayed notion that all "reflections are reflections are reflections" and thus, any/all "sidewall reflections are sidewall reflections are sidewall reflections" without any distinguish-ment between gain, time arrival, sparse, dense/dense-diffused, etc... some here present it as "black and white" - the presence of first-order sidewall energy (ignoring all of the descriptors just mentioned), or no energy at all (attenuated); no ability to distinguish besides that. some present the notion that since they preferred sidewall reflections in this particular room and this particular environment, that that is a blanket catch-all statement for all small bounded acoustical spaces. as if time and gain or the requirement for precise and accurate localization and imaging are not factors at play.


Quote:
Originally Posted by omholt View Post

- Absorption is not the only way to attenuate sidewall-reflections. There are other ways that will not only retain more energy, but actually attenuate reflections even more. It's been used for decades and is something Toole doesn't even seem to mention.

it's been mentioned and eluded to many times over here by some of us, but few seem to 'comprehend' such a simple concept. it is indeed strange that toole does not even briefly mention it, for how long it has been in use. some people here may actually want to surgically limit the amount of broadband absorption within their room, even with the requirement to attenuate specific, indirect signals - as that energy can be managed and used for other purposes, as im sure you're well aware wink.gif


Quote:
Originally Posted by omholt View Post

- Amir tries to make this black and white. The fact is however that Toole researches were not very conclusive.

as evident by his openness in his commentary about it "being a matter of taste" or "this is definitely a case where a personal opinion is permitted." etc, etc ,etc ...

if amir wants to use toole's polls and surveys to get a general idea of what most listeners may "prefer" for his customers and his marketing brochures so they can make purchasing decisions without going through all of the combinations of listening setups, then by all means he is free to do so. but his constant ramming down our throats of what people MUST prefer is the contention we all have with him.

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Originally Posted by omholt View Post

Most people who try dampening early reflections from sidewalls seem to favor it. I havent't seen many who don't. One need to make sure one does it broadband though. Or if the plan is to use diffusion in the rear of the room, one could redirect sidewall reflections instead of dampening. But this is certaintly something you would need to use ETC for. Besides waterfall, ETC is the most useful and important tool to treat small rooms with. Well known in serious acoustic circles for decades. Don't let someone try to persuade you differently.

the fallacy some here have is the equating of the use of a measuring tool (ETC) with a specific acoustical concept or response - when it is not; it is merely a tool. some here have also displayed a spectacular failure of acoustics by insisting that the data within the ETC somehow "tells you what to do". it does not. however, there are an overwhelmingly number of users within this community who are using a mirror to blindly place absorption at any and all possible reflection points - and there is little contention! but once a specific tool is mentioned to allow a user to identify how the ACTUAL indirect specular energy impedes the listening position, and thus allow one to surgically place broadband absorbers (or other attenuation devices) to limit the amount of broadband absorption within the room, then all hell breaks loose! you do NOT see this deep of contention when the mirror is recommended!

very well said, but the bulk of this particular forum is well behind with respect to acoustics (especially small room acoustics) - as such, there is much contention as many are simply unable to learn new concepts, ideas, methods, etc... or anything else that invalidates their previous thought and understanding of acoustics (more specifically, the contention about the relevancy of RTxx in small acoustical spaces that lack a statistically developed reverberant sound-field). basic human nature and teaching old dogs new tricks (lol at the notion of the ETC being a "new trick" - but you get my point!)
post #779 of 871
Quote:
Originally Posted by omholt View Post

I mentioned at a another forum that Toole (or probably his followers to be accurate) has basically brought confusion. I believe this thread shows that exactly. But here the problem also lies in misinterpration of what Toole actually has conveyed.
Something worth mentioning when it comes to the so called favored Toole side-reflections are the following:
- It requires speakers with excellent polar respons. Most don't have that.
- Does Toole say at what time and gain they turn to be beneficial? The arrival in both time and gain are crucial. And from what I've heard from close peers to Toole, he never meant that very early sidewall reflections were something positive. More when they were arriving at late as perhaps 15 ms.
- The researches seem to be conducted in rooms with very little spaciousness. Would the outcome be different if the room was treated differently and especially with the spaciousness arriving form lateral diffusion?
- Absorption is not the only way to attenuate sidewall-reflections. There are other ways that will not only retain more energy, but actually attenuate reflections even more. It's been used for decades and is something Toole doesn't even seem to mention.
- Amir tries to make this black and white. The fact is however that Toole researches were not very conclusive. Whether sidewall reflections were experienced as pleasing or not dependent on the music material. It actually varied quite a bit. Not to mention that this was based on preferences and never accuracy. Here's Toole's own comments on this:
So we see that whether side-wall reflections are something positive or not greatly depends on many factors. Music material, taste, speakers, time of arrival and gain in db, how the rest of the room has been treated etc.
The best way to find out is simply to try it out yourself. Most people who try dampening early reflections from sidewalls seem to favor it. I havent't seen many who don't. One need to make sure one does it broadband though. Or if the plan is to use diffusion in the rear of the room, one could redirect sidewall reflections instead of dampening. But this is certaintly something you would need to use ETC for. Besides waterfall, ETC is the most useful and important tool to treat small rooms with. Well known in serious acoustic circles for decades. Don't let someone try to persuade you differently.
Thanks for posting this. Dr. Toole is a scientist and also practical. What he wrote is also what he said in a class I took at CEDIA. He is again teaching this year and I hope to be able to go.
post #780 of 871
Quote:
Originally Posted by omholt View Post

I mentioned at a another forum that Toole (or probably his followers to be accurate) has basically brought confusion. I believe this thread shows that exactly. But here the problem also lies in misinterpration of what Toole actually has conveyed.
I appreciate you chiming in. I really do smile.gif. But don't you think part of the confusion comes from the fact the people constantly try to parse his few words online rather than spending a few minutes with him in person? If anyone has, you will see that the views that I have expressed on his behalf are expressed even more strongly. Further, it is not just him. But a number of researchers who have worked with him. The first time I actually heard about the beneficial aspects of reflections didn't come from him but Alan Devantier. During this thread, I have quoted research by many other experts pointing to the same view.

Have you read his 17 page AES paper on reflections? Have you read both revisions and how they are both the same view even though it is distanced by many years and more updates in research? You see a consistent view in this area. Here is the summary of the section that deals with speech and reflections:

” 5 EFFECTS OF REFLECTIONS—A SUMMARY
5.1 Speech
Readers who have been keeping score will have noted a distinct absence of negative effects from reflections on any aspect of speech perception we have looked at. In fact, the effects range from neutral to positive. No single reflection has been shown to be a problem for speech reproduction in small rooms (see Table 1). Multiple early reflections contribute even more to intelligibility.” Here is the table he shows:

i-VKC5CNZ-X2.png

The reason people are confused about his views is that they have not read sum total of what he has written and importantly all the research he cites from his team and others. If you read all of that, and spend time with him in person, you see that a strong point of view that emerges. One that is anything but confusing. It is logical from start to finish. It has a beginning and an end. This is what I really like about his teachings. It is not a random chapter that says, "run this tool and then you decide what to do next." He shows conviction in his point of view. He might be wrong but it takes a hell of a lot to prove it than folks show smile.gif.
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Something worth mentioning when it comes to the so called favored Toole side-reflections are the following:
- It requires speakers with excellent polar respons. Most don't have that.
We have covered this point before. Why do you think it is better to keep them and spend hundreds of dollars/time and energy on acosutic products and uglify your listening spaces with them? And where is the evidence that points to people liking absorption there even with those flaws? Earlier I post this research from someone who designs pro spaces: From AES paper titled, LOUDSPEAKERS IN CONTROL ROOMS AND LIVING ROOMS, by George Augspurger:

” Third, I did a lot of listening with various amounts of absorptive treatment in the comers behind the speakers. When first-order reflections were largely absorbed I noted that locations of individual sound sources were more precise, that the timbre of individual instruments was more natural, and that the overall stereo picture was more tightly focused. These observations agree well with other reported listening tests.”

Nonetheless, after extensive listening to classical and pop recordings I went back to the hard, untreated wall surfaces. To my ears the more spacious stereo image more than offset the negative side effects. Other listeners, including many recording engineers, would have preferred the flatter, more tightly focused sound picture.”

Is your theory that George's analysis was also limited to speakers with such good characteristics? How about the Clark study earlier where he clearly stipulates the benefits of side reflections?

Yes, it is true that if you leave the side reflections be and you have crummy off-axis speaker response you will hear that flaw more. That should be fodder to go and upgrade that speaker to something better than to spend years on these forums trying to determine what contraption to stick on the side wall with a hope and a prayer that it somehow mitigates that problem. Earlier I post examples of such poor speaker response and I asked what treatment fixes dips in directivity for example. Nothing came back as an answer: http://www.avsforum.com/t/1413173/does-sound-sounds-better-in-a-room-full-of-furniture-and-stuff-or-without/660#post_22246989

There is a good reason as no answer exists. Acoustic products are not tuned to compensate for a range of frequencies where you woofer starts to beam and with 100% precision. These problems cannot be fixed. Can you get lucky and improve the situation? Maybe. Will that agree with what your ears say was an improvement? Not likely. If your point is that some chance exists for this, then fine. This point of view is not about 100% absolutes but what the preponderance of evidence tells us.
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- Does Toole say at what time and gain they turn to be beneficial? The arrival in both time and gain are crucial. And from what I've heard from close peers to Toole, he never meant that very early sidewall reflections were something positive. More when they were arriving at late as perhaps 15 ms.
From what you have heard of close peers? Why not read his work where this is clearly documented instead of relying on hearsay from unknown sources no less? It is not like this topic is one or two sentences in Dr. Toole’s work. He goes on for 100+ pages (my estimate) in his book alone if you ignore just as much written in his research and that of others referenced. There is no stone unturned. Here is the data you seek as cited from Alan Devantier *from Dr. Toole’s book*:

i-wKXwcMt-X2.png

We see that reflection paths fall in the delay period of under 10 msec. If you think about it, it takes a pretty large room for the delay path to be longer than 10 feet from the direct sound. Such region and gain says that there is some perception of reflections being there and that it contributes to broadening of the source -- a property that is shown time and time again to be beneficial. Some choice quotes from Dr. Toole:

"When listening tests were done in the two versions of the room, it was found that the condition with absorbing side walls was preferred for monitoring of the recording process and examining audio products, whereas reflective side walls (which reduced IACC) were preferred when listeners were simply “enjoying the music.” As might be expected, reflective side walls resulted in a “broadening of the sound image.”

And just yesterday I quoted this from him:

"It was in this room that experience was gained in understanding the role of first reflections from the side walls. The drapes were on tracks, permitting them to easily be brought forward toward the listening area so listeners could compare impressions with natural and attenuated lateral reflections (see Figures 4.10a and 8.8). In stereo listening, the effect would be considered by most as being subtle, but to the extent that there was a preference in terms of sound and imaging quality, the votes favored having the side walls left in a reflective state. In mono listening, the voting definitely favored having the side walls reflective."

And:

"See the discussions in Chapter 8, and Figures 8.1 and 8.2, which show that attenuating first reflections seriously compromises the diffusivity of the sound field and the sense of ASW/image broadening. One of the problems with both music and movies is that sounds that in real life occupy substantial space—multiple musicians or crowds of people, for example—end up being delivered through a single loudspeaker—a tiny, highly localizable source. The precision of the localization is the problem. Most of what we hear in movies and television is monophonic, delivered by the center channel, so a certain amount of locally added room sound may be benefical; this is definitely a case where a personal opinion is permitted."

There is no ambiguity here regarding his point of view.
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- The researches seem to be conducted in rooms with very little spaciousness. Would the outcome be different if the room was treated differently and especially with the spaciousness arriving form lateral diffusion?
Seems to? Why not be specific here? The research and data cited is extensive in support of above views. It covers all manner of situations from single reflection to many. In speech and music. In real rooms and anechoic. But sure, let's have you quote such research and I can comment further.
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- Absorption is not the only way to attenuate sidewall-reflections. There are other ways that will not only retain more energy, but actually attenuate reflections even more. It's been used for decades and is something Toole doesn't even seem to mention.
If you don't say what that is, I can't tell you if he has or has not mentioned it smile.gif. If you mean diffuison by "retaining more energy" then he extensively talks about that and actually recommends it as a method to enhance side reflections. If it is something else, you need to explain it.
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- Amir tries to make this black and white. The fact is however that Toole researches were not very conclusive. Whether sidewall reflections were experienced as pleasing or not dependent on the music material. It actually varied quite a bit.
As I answered Dragon yesterday, it is a campaign slogan to say that a black and white position is taken. What I am black and white about is what Dr. Toole is black and white about. Which is the fact that there is considerable amount of research that points to the right direction here. It is not a wishy-washy thing of running a tool and then flipping a coin as to which direction may be right to take. The mountain of data that points to most people having certain preference is quite strong. It is not 100% and we have already talked about musicians and possibly others not having the same preference. That fact cannot be inverted to say that since the data does not apply to 100% of people, therefore it is a confusing situation and people should sign up for complicated and practically impossible tests to determine their own preference. To wit, none of the vocal posters in this thread have expressed any preference in this regard. If they are so sure of this reality how come no such data has been put forward?

But sure, there is no one here saying you may not have the other preference. Some guys do get to marry super models smile.gif. Go ahead and run the tests and report back. But please don’t say that just because the possibility exists that the research must not have been good, or confusing, or that the probability is equal for both outcomes. None of this is supported given what we know.
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Not to mention that this was based on preferences and never accuracy. Here's Toole's own comments on this:
So we see that whether side-wall reflections are something positive or not greatly depends on many factors. Music material, taste, speakers, time of arrival and gain in db, how the rest of the room has been treated etc.
There is no way you can conclude that from what you quoted from him. Indeed just about everything is in defense of the point of view I have been presenting. The only thing you can hang your hat on is this: ” coincident-mic recordings may benefit from a lack of reflections”. He says “may” benefit in that very narrow case. He goes to talk about his room at NRC with that curtain which I have quoted in more detail above. No one reading that quote will walk away thinking “it all depends.”
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The best way to find out is simply to try it out yourself. Most people who try dampening early reflections from sidewalls seem to favor it.
Who are those people and how do you know that they are not liking the fact that they reduced late reflections which must be done as otherwise the room is too live? An empty listening room is too live and you must have some amount of absorption added to it. When you put a panel at first reflection, you are not just absorbing the first reflection but also all the later ones. You can’t disambiguate those cases. And this assumes your general assertion here is true with no specific and no protocol in gathering such data.
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Or if the plan is to use diffusion in the rear of the room, one could redirect sidewall reflections instead of dampening.
Why would you want diffusion in the back?
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But this is certaintly something you would need to use ETC for. Besides waterfall, ETC is the most useful and important tool to treat small rooms with. Well known in serious acoustic circles for decades. Don't let someone try to persuade you differently.
You mean don’t let Dr. Toole do that? Here he is again:

” The message is that we need to know the spectrum level of reflections to be able to gauge their relative audible effects. This can be done using time-domain representations, like ETC or impulse responses, but it must be done using a method that equates the spectra in all of the spikes in the display, such as bandpass filtering. Examining the “slices” of a waterfall would also be to the point, as would performing FFTs on individual reflections isolated by time windowing of an impulse response. Such processes need to be done with care because of the trade-off between time and frequency resolution, as explained in Section 13.5. It is quite possible to generate meaningless data. All of this is especially relevant in room acoustics because acoustical materials, absorbers, and diffusers routinely modify the spectra of reflected sounds. Whenever the direct and reflected sounds have different spectra, simple broadband ETCs or impulse responses are not trustworthy indicators of audible effects"

I can’t get Dragon or Local to do this. So it would be great if you could tell me once and for all if we should or should not listen to Dr. Toole. He can’t be clearer here about the tool generating "meaningless data.” This proof point has been backed extensively with mathematics of it and experimentation into how we hear. Will you demonstrate why your view and the nameless people in acoustic circles are more right than his?
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