It is better to write what you mean on the internet, instead of being facetious. If you think that uncontrolled listening tests at home are impervious to the usual dangers of uncontrolled experimentation, then state your case.
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I've tried to use the word envelopment as modified by reproduced. And have even recently mentioned that acoustic envelopment is substantially different than reproduced envelopment. ..basically, read a bit more closely.
I'll read through Toole's book again for more precise research conclusions (with cites). It could take me a bit though.
..oh, and I hope those observing a "Labor" day are having a good one!
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For reference with respect to near reflections and tonal changes or “coloration” – we are specifically referencing comb filtering.
9.1.2 final (concluding) paragraph:
“The upshot is that, in any normal room, audible comb filtering is highly improbable. The less “live” the room, the more likely it will be that even a single reflection can be audible as a coloration..”
https://books.google.com/books?id=S...page&q=zurek toole sound reproduction&f=false
9.1.3 explains the problem with inter-channel combing (NOT reflections) and tonal coloration – and ironically the conclusion is that an increase in room reflections LOWERS this problem.
https://books.google.com/books?id=t...s, this is a huge spectral distortion&f=false
10.3 Talks about reflections and intelligibility of speech – basically it improves with more reflections that have a low time interval like a small room does. (..this shouldn’t be a surprise to anyone who has read anything on intelligibility in acoustics within the last 20 years.)
11.1 (Earl this one you should find particularly interesting) - Is angular localization and the contribution of the precedence effect, while there is the potential exception mentioned for unusual listener’s – it’s based on non-stereo playback, the predominate opinion starts at the 5th paragraph in starting with “Important for localization, and very interesting from the perspective of sound reproduction..” (..scroll down to see the major high-lighted portion.)
https://books.google.com/books?id=t...ive of sound toole sound reproduction&f=false
9.1.2 final (concluding) paragraph:
“The upshot is that, in any normal room, audible comb filtering is highly improbable. The less “live” the room, the more likely it will be that even a single reflection can be audible as a coloration..”
https://books.google.com/books?id=S...page&q=zurek toole sound reproduction&f=false
9.1.3 explains the problem with inter-channel combing (NOT reflections) and tonal coloration – and ironically the conclusion is that an increase in room reflections LOWERS this problem.
https://books.google.com/books?id=t...s, this is a huge spectral distortion&f=false
10.3 Talks about reflections and intelligibility of speech – basically it improves with more reflections that have a low time interval like a small room does. (..this shouldn’t be a surprise to anyone who has read anything on intelligibility in acoustics within the last 20 years.)
11.1 (Earl this one you should find particularly interesting) - Is angular localization and the contribution of the precedence effect, while there is the potential exception mentioned for unusual listener’s – it’s based on non-stereo playback, the predominate opinion starts at the 5th paragraph in starting with “Important for localization, and very interesting from the perspective of sound reproduction..” (..scroll down to see the major high-lighted portion.)
https://books.google.com/books?id=t...ive of sound toole sound reproduction&f=false
"Should" means nothing to precedence effect.
Blauert:
https://www.google.com/url?sa=t&rct...sg=AFQjCNFfZNmbv4P6ihNETu3uhsYdA3hCVQ&cad=rja
It tells you what needs be, and is, recorded and therefore has to be reproduced for the listener. The duration of these reflections is long and therefore their level compared to the music is very low. The echoic regime you propose masks them.
tnargs - I do apologize. I thought that my absurd position was well know in these parts.
So let me be clear: I applaud your statements and your position. It is rare to find such an enlightened person in these forums. For the most part what is claimed here is "I know what I hear. Don't confuse me with data." The reality is, of course, quite different and completely in line with your statements.
I think that you "get what I mean" now.
One issue is so many discount DBLT and many other scientific methods. It is hard when technical conversation is sidetracked by anecdotal evidence and conjecture. One of the drivers of that in the audio field is the lack of a coherent set of test protocols that can predict the quality of the final sound production, this brings about the refusal to believe the things that have been proven, it gives an out to those who are looking for magic answers.
Frank - you need to read that qoute from Blaurert a bit more closely - specifically look to what/how the underlying test that is being referenced, specifically the left portion of figure 1.
Also look to the hypothesis presented by Toole in that last link on 11.1 that I provided. (..specifically starting the paragraph with "This appears to be the essence of the observation by Perrot..")
That is the normal test, but there are other ways, maybe better ways.
If you low pass filter a signal and compare it to one with the full bandwidth, that seems a more natural way to test than pure sines. Or, at least, it tells you something different. IMO, more useful.
IME, the same is true for localization tests. Pure tones can be hard to locate. Bandwidth limited noise, much less so.
I agree with Geddes, the 10K-20K octave should not be a big worry. Nice if you've got it, but there are much more important parts of the spectrum. For me >8Khz is mostly important for the warmth in string sounds. It's there I hear the biggest difference.
A big problem with sines is that they have zero bandwidth so that with multipath from reflections off surfaces or diffraction boundaries their energies can be anywhwere from maybe 6dB higher to infinitely lower than you think they should be at some physical position where your ear is. Noise, filtered program material or warble tones mitigate that kind of problem.
I was simply trying to see how high I could hear the highest pure tone, nothing more and it was a single speaker, not a pair. i could clearly hear the 16Khz sine put out by my Clio system, the Earthworks 1/4" M30 mic confirm the frequency. I wasn't trying to localize or anything else, just see where my upper threshold of hearing was. At one time I could hear higher but not anymore. Considering all the loud music I've heard and all the industrial equipment I've been around I thought that was respectable.
Frank - you need to read that qoute from Blaurert a bit more closely - specifically look to what/how the underlying test that is being referenced, specifically the left portion of figure 1.
Also look to the hypothesis presented by Toole in that last link on 11.1 that I provided. (..specifically starting the paragraph with "This appears to be the essence of the observation by Perrot..")
Your 1st paragraph. I read and looked. I can not see what contradicts my claim of colouration due to very early and early lateral reflections. Enlighten me.
2nd para. It seems to me Toole is recommending CD speakers, (elsewhere he has recommended speakers with evenly falling off axis response; oddly, I have never heard of him recommending speakers with both characteristics). Those are Good Things in the context of this discussion as one can use them, toed in, to diminish early lateral reflections and delay and diminish the ipsilateral, yielding comparative increase in direct speaker sound. This latter is good because small room reflections are not just too soon but also too loud compared to direct sound.
The fusion of the direct and reflected sound of the first few milliseconds is just that, fusion. I can't separate them subjectively. I can identify the fusion when it's pathological for the same reasons I can identify old fashioned horn sound - a characteristic timbre, often a continuous or intermittent loss of low level detail, and the loud is too loud and the quiet is too quiet.
Basically, Toole, and you, are recommending we run our rooms too hot.
Frank - thanks very much for the Blauert paper. I was not familiar with it, but it was very enlightening and right on the money.
Scott - while I have great respect for Floyd Toole (I know him well) he and I have always disagreed on this singular point regarding the role of Very Early Reflections (in and just above the fusion region, say 0-3 ms.). IMO Floyd extrapolates the data beyond what I would like to see done. As Frank points out, many other experts like Blauert and Greisinger disagree with him on specifically this point. I also understand that he has much softened his opinion here based on several more recent testing that he has done. So I would say that you need to look to many more authors than just Toole when basing your opinion in this area. You will find that there is not wide agreement on what the very early reflections do.
I believe that they enhance spaciousness (agreed to by Blauert) and they degrade imaging (at least Blauert agrees that they affect timbre). BUT, all this is highly dependent on the nature of the loudspeakers used themselves. They must be low diffraction (< 1 ms) and high DI constant directivity or the toe-in technic will not work properly. But given the above two factors in the loudspeakers (which are very rare I might add) minimizing the first near wall reflection with narrow directivity toe-in will create a very wide sweat spot with superb imaging aspects. This will lower spaciousness however, but this can be retrieved with a very lively room.
Scott - while I have great respect for Floyd Toole (I know him well) he and I have always disagreed on this singular point regarding the role of Very Early Reflections (in and just above the fusion region, say 0-3 ms.). IMO Floyd extrapolates the data beyond what I would like to see done. As Frank points out, many other experts like Blauert and Greisinger disagree with him on specifically this point. I also understand that he has much softened his opinion here based on several more recent testing that he has done. So I would say that you need to look to many more authors than just Toole when basing your opinion in this area. You will find that there is not wide agreement on what the very early reflections do.
I believe that they enhance spaciousness (agreed to by Blauert) and they degrade imaging (at least Blauert agrees that they affect timbre). BUT, all this is highly dependent on the nature of the loudspeakers used themselves. They must be low diffraction (< 1 ms) and high DI constant directivity or the toe-in technic will not work properly. But given the above two factors in the loudspeakers (which are very rare I might add) minimizing the first near wall reflection with narrow directivity toe-in will create a very wide sweat spot with superb imaging aspects. This will lower spaciousness however, but this can be retrieved with a very lively room.
Yes, audiologists use pure tones, but there are no industry accepted techniques for measuring hearing above 8 kHz. As far as speech is concerned anything above this is simply irrelevant. It seems to me that if our hearing finds these signals irrelevant for speech, then they simply can't be that important for music.
Earl,
I just can't make the connection between speech acuity and listening to music. If that was the case about anything about 8Khz then we could just low pass filter that out and not notice a real perceptible difference in tone and the impulse response of so many instruments. I find it hard to believe that a cymbal or a horn would sound correct without those upper frequencies about 8Khz. Now whether the phase response needs to be linear would be a separate issue to consider.
I just can't make the connection between speech acuity and listening to music. If that was the case about anything about 8Khz then we could just low pass filter that out and not notice a real perceptible difference in tone and the impulse response of so many instruments. I find it hard to believe that a cymbal or a horn would sound correct without those upper frequencies about 8Khz. Now whether the phase response needs to be linear would be a separate issue to consider.
I respectfully disagree
early reflections control the illusions of width and depth and they should be controlled
see LEDE concept. AES E-Library The LEDE- Concept for the Control of Acoustic and Psychoacoustic Parameters in Recording Control Rooms
I think that you are stretching what I said. The "importance" of the content above 8 kHz is falling, not that a careful listening could not be detected. But it is true that Fraunhoffer Labs studied this problem with exactly the same test that you describe and found that somewhere in the 12 kHz range the detection rate fell to only about 10% of the sources and subjects. It is not possible, nor does it make any sense, to view this issue as finding the limit beyond which no one could ever detect it for any possible source material. Science doesn't work like that.
And someone can think and even claim that they are sensitive to a 1% limit, but then does it really make sense to worry about it.
And someone can think and even claim that they are sensitive to a 1% limit, but then does it really make sense to worry about it.
The question is not "can i hear this" but rather " is this significant"
to test your hearing try switching between a sine and a square wave at 5KHz
that will test for audibility at 15KHz.
I have done this with 15KHz sine and square waves.
I could hear the difference.
The difference was a 45KHz third harmonic which i clearly heard .
I tested to be sure only 45KHz and higher sounds were present using a 1/4" B&K microphone and a HP FFT analyzer
Not everyone can hear this .
is this significant?
not really
it is incredibly rare to have any sounds recorded that high.