Originally Posted by amirm
“Fight from reality” is a nice froydian slip
. The fixtures do exist. I have seen them and they are not difficult to build at all. Yes, it requires motors/hydraulics to move things behind a curtain but readily doable. As long as someone has done and easily so, there is no excuse but laziness and escape from the truth that it holds.
Sure, if you are an individual not in the business then it is fine to say you don't have the means to conduct such tests. But if you are a person in the industry like Ethan then this is something you need to do if you are going to say there are improvements relative to the products you offer for sale. Even if it were hard, it is not our jobs as customers to make it easy for you. Either you follow the research or you show objective data saying otherwise.
By the way, there are a number of ways to simulate these things that don’t involve anything physical. One of the common ways is to use an anechoic chamber and then use one or more speakers that represent the reflections. Under electronic control you can change what the secondary speakers play and with it, what the reflections will be in a real room. To test a first reflection for example, you put a speaker at that imaginary wall position and then feed the same signal that is going to the main speaker but delayed and or transformed to the one representing the reflection. The switch over is instant then.
And it is not just double blind data that is lacking but also objective measurements. Dragon says he has been doing this work for 25 years. During all that time, he couldn't be bothered to make one measurement to post here? Or one double blind test? Has he toured Harman facility and can tell us why it is impossible to build such fixtures? Has he reviewed countless tests documented in the literature using the techniques I mentioned above? Have you?
Please leave the misdirection for others Arny. This is an acoustic topic. I am asking for objective data to back people's claims that are contrary to *published* research and double blind tests. And you are making excuses in post after post as to why not. As I showed from the quote of professor Cox white paper, people are indeed selling diffusers which cannot work as a matter of math. You show no outrage regarding that. You show no outrage that people call double blind tests surveys. You show no outrage that AES papers are called marketing brochures. As a guy who advocates these things all the time, it makes for a poor showing.
Oh they most definitely are. What do you think the arguments have been about in this thread? One guy says comb filtering is bad, and a top expert in the industry says it isn't. One guy says to use time domain analysis and the top industry expert says it is a waste of time. Let's put me aside. Here in an interaction from the first page of this thread:
You say there is a priority and he says it isn't. Which is it? Clearly there is substantial disagreement here and not over tiny things. The whole notion of how we approach this topic is hugely disputed. Dr. Toole says typical living room doesn’t need treatment. Ethan violently disagrees if a picture of any listening room is shown without acoustic products. I would say there is more dispute here than any other audio topic I have seen. Just a page ago someone asked where to put diffusers and absorbers. You want to bet no matter who answers there will be an argument and a bitter one at that?
How do we get past disagreements like this in audio? We ask for measurements, explanation of science and double blind testing. Then we triangulate and decide what is right in our mind. I have looked the camps here and the only one that provides all of this is Dr. Toole and Harman group. The others throw stuff out there and say, “there, it is a problem. “ When I ask them to show it, they get personal. And you chime in of all people defending them that they shouldn’t provide these things? I mean where is one measurement that these posters have done themselves? I must have asked Dragon and Localhost half a dozen times and nothing comes forward. Yet you are arguing with me and not them.
Let’s look at this example:
You are telling me this is not controversial? If so, why does Ethan have graphs on his site and full videos saying side-wall reflections create comb-filtering that should be cured with acoustic panels? Why doesn't the video say the opposite, that double blind tests show preference here despite the ugliness of the measurement?
I am advocating easy ones here too. Put a curtain in front of your side wall, have a person stand behind it and move a panel in and out of place while you vote on whether it does something good or not. How hard is that? But sure, if it is hard, then rely on others who have done the work for you as I do. Don’t disagree and then complain that it is hard. If a car company crash tested two cars and found theirs to do better your answer can’t be that they are wrong but it is too hard for you to do the same test.
And it is not just a matter of double blind tests. It seems that I am the only one talking about whether a distortion is perceptually audible. Everyone else wants to put forward a microphone and a graph to prove their case. No talk of perceptual effects. When I quote industry experts in this area, they call people who listen to them a cult. See Dragon's statement here: http://www.avsforum.com/avs-vb/showt...#post21865114:
"Ah, the cult of Toole. So quaint and so limited. A cult? Limited because we dare to believe a comprehensive thesis?
Here is the type of teaching Dragon says we should not care about: http://www.avsforum.com/avs-vb/showt...6#post21834576
I could swear your position on measurements was that we should not care if we can't prove they are audible. Yet any discussion of that is dismissed and folks want to insist they are right to look at a single microphone and a graph representing the audible distortion. Well, it doesn't work for me. But it is surprising that it does for you.
You mean if anyone cared to correlate audible effects with measurements it would be Harman.
People assemble large factories building automated systems to fabricate speakers or acoustic products (seem to recall CNC machinery in Ethan’s shop). Yet somehow don't know how to rotate something physical in and out of place behind a curtain to learn more about what we hear???
Wow. And as is so typical, not one acoustical concept is discussed. Its all about the tyranny of a subjective survey of selected listeners.
The same attempts to bludgeon others into accepting the one-size-fits all mindset advocating a paradigm that is neither universal in preference or application, as well as an ill formed process for actually achieving an acoustic response that is lacking any available systematic objective performance metrics enabling one to actively evaluate a space and to objectively determine compliance except for a few graphs of generalized perception levels which are little more than restatements or slight modifications of those long available.
All of that as one attempts to posit Toole's approach as the paradigm, when even Toole admits that it is simply but one approach preferred by some, but neither optimal or even appropriate for various other purposes including 2channel versus surround or critical listening versus 'big' fuzzy special FX...
The irony is that we have earlier attempted to present the means as well as some of the various major acoustical response models that are generally suitable for quite a few applications. And they are not the only options. And one can then, depending upon their application and preference, use the tools to hopefully achieve the response characteristic the desire that best elicits the acoustical response they desire.
The irony is that what Toole proposes is NOT new. And the concerns he worries about such as spectral imbalance are valid but old news as well, wherein much of the the rest of the industry was already aware of the issues and was glad to see him validate the concepts for himself.
But his PREFERENCE is only ONE possible response. It is one where the early arriving soundfield sacrifices accuracy and precise imaging for large fuzzy imaging that, yes, some people prefer. It adds nothing to the later laterally arriving diffuse soundfield that was well developed 30 years ago.
What is different is that someone here has recently discovered the concepts, and has failed to understand the context from which they emerged, and being largely ignorant of the progression of research and alternative models designed for various applications and preferences (as well as the actual concepts involved) now attempts to elevate this variant to the status of the ONLY valid model.
I personally have no problem with what Toole advocates as far as it goes. I personally prefer a more accurate imaging augmented by a diffuse sense of spaciousness and envelopment. It suits me for both critical listening professional use, 2 channel as well as surround, and for casual listening.
I am also quite capable of helping others to understand and to optimally achieve various other acoustic response models and everything in between by virtue that I not only understand the various response components that constitute each, but also a myriad ways in which they can be creatively achieved.
(Ironically, seasoned professionals have opted against exactly such a surround environment on steroids at Blackbird Studio C as the front and side diffusors have been draped with packing blankets rendering them absorbers in order to tighter the image while still providing a later arriving diffuse sense of envelopment and spaciousness. But hey, what do they know?)
But this flies in the face of someone who only accepts one model and who, by virtue of some subjective listening tests attempts to impose the tyranny of a few who regardless of context and use now attempts to force everyone else, whatever their purpose or preference to submit to a few who like big spectacular fuzzy imaging.
We get it. You like it. Unfortunately, short of simply cutting and pasting, you display little actual knowledge of the acoustical concepts at play, and even less understanding of many of the tools and myriad processes by which such responses can be achieved (oh, I know, just give you some time to go find a paragraph someone else wrote to quote...). Unfortunately, there has been almost NO actual discussion of concepts or addressing specifics, simply as one party cannot offer this. Instead what is substituted is the cheerleading of one particular point of view that assumes 'ideal' power responses - but which is severely constrained when one must deal with 'real' speakers featuring anything less, aside from quotes denigrating such use - which ALL have known about long before Toole even began his professional career!
Hell, that concept of uniform power response and controlled dispersion was a pre-requisite cornerstone for Don Davis and Tom Hidley as well - long before Toole arrived! Just as was uniform power response truly diffuse diffusors before they actually existed as well!) And as a result of the lack of the existence of such transducers, they advocated real world controlled Q devises whose power response over the available dispersive range was uniform.
And all while simultaneously advocating the same use of broadband treatment to mitigate boundary anomalies resulting from adverse high gain reflections, all Toole offers is denigration of practical treatments used to re-mediate exactly such REAL problems resulting from the use of REAL existing speakers from the period, as he, in hindsight, decries the lack of use of then non-existent ideal uniform power response speakers!
Wow, now that takes guts and knowledge! Especially as it also ignores the fact that the response model he attacks for not using his technique was also optimized for 2 channel
Gee, I wonder why he has also not chastised Edison's testing filament materials lacking the efficiency and longevity for not using technology that is only now available! So tell us, what speaker had an 'ideal' uniform 180 degree power response in 1977? (Hint, the Heil AMT configuration was 'close'...) So let's see the cut an past machine go to work now!
Prefer whatever you want.
But it takes a bit more insight and knowledge to understand the fundamental concepts at play, and to understand how various response models can similarly be preferred by many for a multitude of differing applications. And it takes a bit more to be able to evaluate various applications in conjunction with the PREFERENCE of the person who is paying for the design and realization of such an environment so as to achieve a final result whose performance satisfies THEIR desired preference than it does to simply tell everyone that one size fits all - regardless of the application and desires of the person whose preference is paramount.