To me it is. Look at the app on my website and you will see how this can be beneficial and how for many speakers it is a real problem while for others it doesn't do much of anything.
Absolutism is not beneficial. You do "the best you can" that's the "best you can do". Asking about the unobtainable extreme is a waste of time IMO. But we have been through this before -Markus we don't agree. I deal in realities and you deal in perfection. How's that working out for you?
I would use diffusion (dispersion is another thing), never absorption. Small room are inherently absorptive, too absorptive, and adding more just makes them dead. They sound small and feel claustrophobic.
I found it to have a detrimental effect. Might be a level difference caused by different room geometries. Would you mind posting a floor plan of your room that shows speaker and listening position?
Your perceptions are seldom the same as most of the rest of us.
My room is 14 ft. by 23 ft. The speakers are three ft. out of the corners (both walls) and toed in at 45 degrees. I don't think that a drawing would make it any clearer. There is nothing in the front of the room forward of the listening seats except the speakers (subs in corners behind the mains).
I don't use nor do I believe in bass traps. They are not effective enough - my whole room walls are dampers - LF only. The corners are better places for subs.
I know that most rooms aren't built like mine - but they could be. What would I do in a normal room? Maybe rebuild it. Its easier than most people think. But band-aids to a common disastrous room? I don't have much experience with that. I don't do band-aids.
I have, several times. But some people simply refuse to believe it. Shrug - what can you do?
With pure tones I find localization difficult at any frequency. With band limited noise, it can be done done to about 80Hz or lower. I can do further tests with speakers and ears that are not mine, if anyone cares. But I doubt that will change any minds.
You could explain what you do (in-room-situation, musical content etc.) and what you hear. Griesinger does not speak about band limited noise, but music and speech afaik.
Rudolf
When your results differ so markedly from other experts in the field it does make one wonder.
Quite correct. Band limited noise may be an entirely different thing. It would not fit into his "phase of the harmonics" paradym.
I would think the proper test would be to create a signal with a fundamental at say 200 Hz and maybe 10 harmonics. Then delete the 200 and 400 Hz ones and see if the localization degrades. That's really the test that proves or disproves the claims, not that one can or cannot localize some signal below 700 Hz, only that below 700 Hz adds almost nothing to your localization ability. It is dominated by > 700 Hz. Thats the claim.
My belief is that the ear localises on the defects in the sound, rather than the "pure" tones. The distortion in the playback which is unrelated to the musical performance is sufficient for the ear/brain to use to "cleverly" locate the source of the sound. Clean sound contains insufficient information which is acoustically unrelated to the main signal for the brain to use to do the job.
I would suggest that the experts normally use playback which is insufficiently "pure" to observe this effect. Has any research been done that directly measures the impact of distortion levels on the sort of results mentioned here, focuses on that as the key variable to be investigated?
Frank
Earl,
Again we actually agree on something. I agree that the frequencies >700hz are going to be the dominant localization ques. That I can agree on, and also lacking those frequencies >700hz we can still localize a sound down to possibly as low as 150hz. That seems like a better statement and very believable in practice.
Now what Frank is trying to say seems to be a different phenomena. I am not sure that we use distortion as a localization function so much as we will be aware of any frequencies that are not correlated to the fundamentals and harmonics of those fundamentals. We will clue into those sounds more because they just don't relate to the rest of the harmonic structure, if I am saying that with any clarity?
Frank if you would want to do that as a test I would say you would take a frequency and add perhaps the 2nd and 3rd harmonic frequency as a sine wave and just add in an unrelated frequency and do your test. I don't know what it would prove except that you would be aware of the uncorrelated harmonic frequency. How is this any different than somebody playing a guitar with one string that is out of tune? That is just something that you are instantly aware of, but I am not sure I would say that this would dominate any localization unless it was in the band where our hearing is the most acute or was at a higher spl level where it would instantly stand out?
Again we actually agree on something. I agree that the frequencies >700hz are going to be the dominant localization ques. That I can agree on, and also lacking those frequencies >700hz we can still localize a sound down to possibly as low as 150hz. That seems like a better statement and very believable in practice.
Now what Frank is trying to say seems to be a different phenomena. I am not sure that we use distortion as a localization function so much as we will be aware of any frequencies that are not correlated to the fundamentals and harmonics of those fundamentals. We will clue into those sounds more because they just don't relate to the rest of the harmonic structure, if I am saying that with any clarity?
Frank if you would want to do that as a test I would say you would take a frequency and add perhaps the 2nd and 3rd harmonic frequency as a sine wave and just add in an unrelated frequency and do your test. I don't know what it would prove except that you would be aware of the uncorrelated harmonic frequency. How is this any different than somebody playing a guitar with one string that is out of tune? That is just something that you are instantly aware of, but I am not sure I would say that this would dominate any localization unless it was in the band where our hearing is the most acute or was at a higher spl level where it would instantly stand out?
Frank and Kindhornman
Thats all fine, but irrelavent. The fact reamins that the dominate source of localization cues are > 700 Hz - thats all I have ever said. The details of the extreme exceptions are not relavent - to me at least.
But remember that a simple test with one subject does not vaildate or invalidate anything. That's why using test results are such a weak support. When the hypothesis holds together under all validated known data then it is worth considering and taking seriously. It may be some time before it is proven, thats the way of science, but good scientists know when a new theory "fits" - and Greisingers theory "fits".
Thats all fine, but irrelavent. The fact reamins that the dominate source of localization cues are > 700 Hz - thats all I have ever said. The details of the extreme exceptions are not relavent - to me at least.
But remember that a simple test with one subject does not vaildate or invalidate anything. That's why using test results are such a weak support. When the hypothesis holds together under all validated known data then it is worth considering and taking seriously. It may be some time before it is proven, thats the way of science, but good scientists know when a new theory "fits" - and Greisingers theory "fits".
From an energy absorption and dissipation point, I fail to see how this can be true for small rooms. However, considering absorption, when you have a lot, and the playback does not sound right, I think one needs to look for problems in other areas of the reproduction system.
Earl,
Many scientist also fall for theoretical explanations that fit their own preconceived notions of what they expect and then those theories are found later to be incorrect. So you are just saying that Greisingers theory fits the solution you are looking for. A proof and a theory are two different things. We have many competing theories about much that goes on with human hearing and not many proofs. We see that all the time in astrophysics, a theory postulated and believed by many scientist's and later found to be completely incorrect.
ps. What is the absorptive properties of drywall an how are you saying that a typical room has such high losses? I won't argue that bass frequency leakage isn't fairly high, but at high spl levels I would think that it is still rather a low loss factor we are looking at. Seems that a drywall or plaster wall or even a block wall would have a low enough loss factor that we could still want to increase the losses.
Many scientist also fall for theoretical explanations that fit their own preconceived notions of what they expect and then those theories are found later to be incorrect. So you are just saying that Greisingers theory fits the solution you are looking for. A proof and a theory are two different things. We have many competing theories about much that goes on with human hearing and not many proofs. We see that all the time in astrophysics, a theory postulated and believed by many scientist's and later found to be completely incorrect.
ps. What is the absorptive properties of drywall an how are you saying that a typical room has such high losses? I won't argue that bass frequency leakage isn't fairly high, but at high spl levels I would think that it is still rather a low loss factor we are looking at. Seems that a drywall or plaster wall or even a block wall would have a low enough loss factor that we could still want to increase the losses.
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A small concrete room is inherently more absorptive than a larger concrete room? What a laugh!
Good scientist know when a new theory fits: Good scientists recreate experiments based on concise descriptions and compare results. You're giving me great laughs.
It's true, that the dominate source of localization cues are > 700 Hz, assuming the source extends higher in freq. and has a significant intensity level. Rather a large amount of really good research to back this up.
HOWEVER,
"Imaging" can often be comprised of original sources with spectral content that does not extend to 700 Hz with any significant intensity.
That's not really an "extreme exception", and it is obviously relevant.