There's essentially zero recorded audio that's up past 20 kHz, and almost no one can reliably hear even pure tones at 20+ kHz.
True .......... but the bones in our head can sense
40 kHz as a sense of space.
I cannot hear very high at all but can still sense if
highs are present.
Is that flat to 40kHz? Wouldn't 80kHz give more accurate reproduction? 😉
-2dB at 20kHz typical, I think the 1/4" mics are too noisy. I guess recording engineers have their own posses Harvey Gerst thinks the B&K mics are too analytical and dry.
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That's what I found looking at the B&K mics, and the smaller ones seem to be for measurement?
I don't see how the highs give a sense of space (depth?) isn't that due to reverberation mainly?True .......... but the bones in our head can sense
40 kHz as a sense of space.
I cannot hear very high at all but can still sense if
highs are present.
From one of the references given in the Boyk paper - a 2001 Thesis by Daniel Cheever
"A NEW METHODOLOGY FOR AUDIO FREQUENCY
POWER AMPLIFIER TESTING BASED ON PSYCHOACOUSTIC
DATA THAT BETTER CORRELATES WITH SOUND QUALITY"
Although this paper is concerned with the effects of feedback on amplifiers, there are other ways that noise modulation is created in playback systems & is subjectively perceived as a flattening of the sound, less dynamic, less aliveness, less naturalness.
Again, as mentioned in that extract, it's the processing involved in auditory perception that reveals this - no measurement is currently capable of doing so
"A NEW METHODOLOGY FOR AUDIO FREQUENCY
POWER AMPLIFIER TESTING BASED ON PSYCHOACOUSTIC
DATA THAT BETTER CORRELATES WITH SOUND QUALITY"
Pre-transient Noise Bursts
The noise burst detected during the first few 10ths of a second in a complex
percussive sound like a piano or harpsichord has been shown to be a key element in the
recognition process [37 pp. 153]. The brain has a very complex multi-tone intelligibility
engine, but at a certain threshold the additional random vibrations (noise) the neural
processing mechanism simply gives up. I propose that feedback in and of itself creates
levels of intermodulation distortion that modulate and otherwise confuse the noise bursts
of musical instruments, leading to a subjective response that the sound is “artificial”. An
example would be the inability of even the finest instrumentation being able to quantify
the difference between a Stradivarius violin and a more modest instrument [37 pp. 111]
.
Indeed the string player has the ability to introduce extremely fine changes in timbre. Our
brain has learned to build up the corresponding identifying readout patterns based on
tremendously refined information processing. We are able to recognize minute,
unmeasurable, fine structures of the acoustical signal. If these fine structures are
unmeasurable in the live acoustical field via a direct feed into the analyzing instrument it follows that we are unable to determine if electronics are transparent in this regard!
Indeed there exists currently no methodology that specifically analyzes the fidelity of a
noise burst buried in a tone transient.
Although this paper is concerned with the effects of feedback on amplifiers, there are other ways that noise modulation is created in playback systems & is subjectively perceived as a flattening of the sound, less dynamic, less aliveness, less naturalness.
Again, as mentioned in that extract, it's the processing involved in auditory perception that reveals this - no measurement is currently capable of doing so
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Funny that Stradivarius quote given that there was a test done where, when blindfolded Violinists couldn't tell a strad from a cheapy either.
As for 'no measurement is capable' we can measure things a lot more complex than a violin. I think it might be very much more accurate to say 'no one can be arsed to work out how to measure'
As for 'no measurement is capable' we can measure things a lot more complex than a violin. I think it might be very much more accurate to say 'no one can be arsed to work out how to measure'
Cheever's thesis has been discussed here before, it has several things in it that are just plain wrong (very wrong), and I know you know how to use the search function when you want to. 😉
I just did a search on here & see Cheever's thesis was referenced before - some supporting it & some criticizing it.
I'm not so much interested in the global feedback Vs no feedback debate - more interested in what he & Boyk identify as noise modulation & its perceptual effects on audio playback. They both concur with my own perception of what I believe removal of noise modulation results in - as I said before a more believable sound with realistic perceived dynamics. One thing that I didn't read in either paper was a solidity to the soundstage & solidity to individual instruments/voices in that soundstage. There are good explanations for this that are hinted at in Cheevers paper
Again, I have not seen any determined & successful effort at measuring noise modulation in dynamic signal playback - I would welcome correction if I'm mistaken about this
I'm not so much interested in the global feedback Vs no feedback debate - more interested in what he & Boyk identify as noise modulation & its perceptual effects on audio playback. They both concur with my own perception of what I believe removal of noise modulation results in - as I said before a more believable sound with realistic perceived dynamics. One thing that I didn't read in either paper was a solidity to the soundstage & solidity to individual instruments/voices in that soundstage. There are good explanations for this that are hinted at in Cheevers paper
Again, I have not seen any determined & successful effort at measuring noise modulation in dynamic signal playback - I would welcome correction if I'm mistaken about this
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Yea, I seem to remember they not only blindfolded the violinists but used a hotel room, disguised any possible hints of smell with perfume & some other time restrictions - an assault on the senses & introduction of stress in time & room & other stuff I can't remember - an obvious way NOT to do a perceptual testFunny that Stradivarius quote given that there was a test done where, when blindfolded Violinists couldn't tell a strad from a cheapy either.
They know nothing about perceptual testing, as per usual
Yes, I accept your correction but would change it slightly to remove the pejorative "can be arsed" to "no measurements have yet been devised to measure noise modulation in music signal playback"As for 'no measurement is capable' we can measure things a lot more complex than a violin. I think it might be very much more accurate to say 'no one can be arsed to work out how to measure'
Once one has decided something is unmeasurable then any response can be deemed... https://www.youtube.com/watch?v=siAkfXf1TQc
I would call that unlistenable, not unutterable 😱Once one has decided something is unmeasurable then any response can be deemed... https://www.youtube.com/watch?v=siAkfXf1TQc
They both concur with my own perception of what I believe removal of noise modulation results in - as I said before a more believable sound with realistic perceived dynamics.
That's a reasonable hypothesis, I once thought the multi-tone test would be more telling but I have seen several loop-backs that show virtually no noise floor at any level. I know there is enough computing power now to generate some more interesting test waveforms with FFT filtered real music. I should be back on line early in the new year if all goes well.
No this was the 2012 Paris test, you are referring to the 2010 Indianapolis test.Yea, I seem to remember they not only blindfolded the violinists but used a hotel room, disguised any possible hints of smell with perfume & some other time restrictions - an assault on the senses & introduction of stress in time & room & other stuff I can't remember - an obvious way NOT to do a perceptual
Yes, I accept your correction but would change it slightly to remove the pejorative "can be arsed" to "no measurements have yet been devised to measure noise modulation in music signal playback"
No, the sort of people who could do this generally cannot be arsed. There are more interesting things to be measured, like gravitational waves, and which way antimatter moves in a gravitational field. Real Science and Engineering. Audio doesn't trouble the greatest minds much.
Most of those who measure audio stuff have a vested interest in not finding this out. People who could measure it (like Bruce Hofer) haven't been paid to work out the test.
Once one has decided something is unmeasurable then any response can be deemed... https://www.youtube.com/watch?v=siAkfXf1TQc
Mark E. Smith just keeps on going. I see they've banned Waly.
That's a reasonable hypothesis, I once thought the multi-tone test would be more telling but I have seen several loop-backs that show virtually no noise floor at any level. I know there is enough computing power now to generate some more interesting test waveforms with FFT filtered real music. I should be back on line early in the new year if all goes well.
Yes, I thought multitone would be closer to reveal noise modulation but it doesn't address the modulation aspect which requires some dynamic changing of the signal - I wonder has a dynamic multitone ever been done - maybe amplitude modulating each tone while keeping the overall crest factor unchanged?
What do you intend by "FFT filtered real music"?
I remember Eldam, when I first came to this site I had some good interaction with him, he was very passionate though which was his undoing in the end, I miss him. Waly always struck me as a very smart guy.
Yes, I thought multitone would be closer to reveal noise modulation but it doesn't address the modulation aspect which requires some dynamic changing of the signal - I wonder has a dynamic multitone ever been done - maybe amplitude modulating each tone while keeping the overall crest factor unchanged?
What do you intend by "FFT filtered real music"?
I would take some dynamic music and remove narrow groups of bins, not sure yet how wide or how many or if linear or log spacing is best. You should be able to preserve the crest factor and dynamics but have these places where nothing should show up. It's easy today to just take a full 20 or 30 second cut of music at 96kHz and do a one shot filter so the empty bins are really empty and have no mathematical leakage. This is just a thought experiment that is easy to do, not sure if it would show anything interesting or how to interpret it.
I see they've banned Waly.
I would like to publicly brag that I predicted Waly would get banned: my prediction was mode on 06 May 2016: LINK
In that delightful thread, Waly VERY CONFIDENTLY proclaims that MOSFET gm is not equal to dIds/dVgs . Brave and stupid at the same time. Technical management in my part of the world (Silicon Valley) often describes people with this personality defect, as follows:
Often wrong, but never in doubt.
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