I'll enlighten you. You don't hear a difference, you imagine one. Show some proof, proper blind testing.
The usual reason. Ego. Nothing like a blind test to show you you don't have super hearing. Self delusion is a powerful thing.
What he posts online needs to be taken with more than a grain of salt as he has a business agenda to push.
Jakob2: "there are ties, as audio development was and is part of my work."
What about them? Measure them? The lack of a measurement doesn't mean there's something wrong with the world.
I don't disagree.
Engineers do understand that, simply because there are no published standardized threasholds of audibility for anything, only rought estimates. Most engineering measurements are relative to a reference.
If you have a specific instance, we could look at it, but the variability in test subjects is part of the data. Often the final analysis returns a "range of normal", plus high and low, rarely are there single figure absolutes. That doesn't mean the study is a failure, on the contrary, it's returning good data.
It's not.
Good questions. I'm not sure we can't predict how an amplifier will sound once it's in isolation from non-audio biases. There are a number of non-traditional measurements that can and should be done. Again, reference the Jensen AES paper regarding "spectral contamination". The good thing is that's an easy test now, it was very difficult when the paper was written.
Where did all of that come from? And while "phase noise" may impact the reconstructed (hardly convolved though) audio, it's once again not a binary quantity, but a question of degree. And easily measured, BTW. In DACs I've tested, it's simply a non-factor. No, noise is not constantly changing. It doesn't work like that.
No, masking is quite well understood, and wouldn't apply here.
That would be a research project, possibly already done.
It doesn't matterr if it's inaudible to every single human on earth. There will always be a weird human you can't include in the test. This is true in every branch of science, there's always a bit of imprecision, you just need to know it's a possibility. It won't change device design.
Phase noise, or jitter, is quite easily measured. Even REW will do it. Not a problem for AP.
Because you can't do that. Stereo recording is not replication, it's creating an illusion of an event, real or synthetic, that is adequate enough to suspend disbelief. Because it's not replication of the original event, there is no means to quantify it, the "reference" doesn't apply. It's subjective. You can collect subjective data and analyze it statistically of course. You just can't measure this objectively directly.
No, it doesn't. I have an example of exactly that, a sine wave with several harmonics, then with some rather significant (and unnatural) application of phase shift. The spectrum and the audible sound quality do not change. Phase is something humans are not very sensitive to. It gets sighted a lot because it's not easily understood and somewhat challenging to measure.
I don't know, ask ASR?
Why do you keep assuming that engineers are fools? Engineers are usually very detaild and methodical. This goes down the path of "we don't know everything" and "engeers don't understand audio".
Wow. If you need to take that road, I'm not going with you.
See there are some questions and comments I need to respond to. Probably have to wait until tomorrow for most of it.
For now, regarding dacs and close-in phase noise, that sort of phase noise is often distinguished from jitter in the literature (including in various app notes. Perhaps the different treatment is because different measurement instruments may be needed, and because practical side effects of the the noise can be different).
If it would help get some intuitive feel for close-in phase noise as verses jitter, I will attach a brochure containing some graphical illustration. Mathematical treatment is also available but perhaps less intuitive. In the case of audio dacs, close-in phase noise can fall within the audio band.
Regarding a question from someone else about IMD, maybe I am still trying to figure out why pretty low level IMD can audible with music signals if one knows what to listen for (willing to adjust my conjectures re causation as time goes on). lrisbo comments about sensitive midrange frequencies affecting IMD discrimination may have been what I was looking for. Turns out that for me chordal textures in music subtly change in a way correlated with measurements of low level HD, including for low order HD. As lrisbo said about hysteresis distortion, I think other people can be trained to know what to listen for.
More to come.
For now, regarding dacs and close-in phase noise, that sort of phase noise is often distinguished from jitter in the literature (including in various app notes. Perhaps the different treatment is because different measurement instruments may be needed, and because practical side effects of the the noise can be different).
If it would help get some intuitive feel for close-in phase noise as verses jitter, I will attach a brochure containing some graphical illustration. Mathematical treatment is also available but perhaps less intuitive. In the case of audio dacs, close-in phase noise can fall within the audio band.
Regarding a question from someone else about IMD, maybe I am still trying to figure out why pretty low level IMD can audible with music signals if one knows what to listen for (willing to adjust my conjectures re causation as time goes on). lrisbo comments about sensitive midrange frequencies affecting IMD discrimination may have been what I was looking for. Turns out that for me chordal textures in music subtly change in a way correlated with measurements of low level HD, including for low order HD. As lrisbo said about hysteresis distortion, I think other people can be trained to know what to listen for.
More to come.
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First thing first, make sure it's audible in level matched double blind listening test. Anything other than that is just a conjecture to begin with. Imagine that, searching for causation in conjecture.
Mr. Fahey, I did respond to the OP about the resistors in question.
Other than that if the discussion bothers you, why torture yourself bothering to read it?
Other than that if the discussion bothers you, why torture yourself bothering to read it?
Perhaps because you posted, "IME LT196 and many other LDO voltage regulators tend fare poorly in subjective listening tests. There are only a very few IME that are exceptions. This is nothing new and did not start with me. Still do my own listening tests anyway, and report what I find. People are free to take it or leave it. Other than that the S/N ratio in here is starting decline. Anyone interested in further discussion on the matter is free to PM." and "Sorry the thread got sidetracked. If you have questions you would like to discuss without extra commotion, please feel free to send me a PM."
A carrier amplitude modulated by a single frequency has only two sidebands. You can shift their phase or not, still only two. A FM carrier modulated by a single frequency has a theoretically infinite number of sidbands, but they are a representation on a spectrum analyzer, which does not, and cannot show actual frequency modulation.
My point is, your AM example has too many sidebands for a single modulating frequency, so what was the modulation signal?
"Phase noise" and "jitter" are both FM functions. They are different only in the nature of the modulating frequency. The measurement techniques do not differ. The audible effects depend on the character of the modulating signal.
I see nothing new or useful in that document.
IMD tends to be more audible than THD because the products generated are not harmonically related to the desired signal, and unlikely masked by other musically related sounds. That makes them stand out as unique and objectionable. Again, nothing new here. This has been known for many decades.
Not. Unless the specific resistor is selected in error and not appropriate for the application.
A couple of things. Maybe MarcelvdG could chime in and explain to jaddie about close-in phase noise as opposed to jitter as the are classified in dac work. Of course we all know they are subclassifactions of the same basic physical phenomenon. Jitter can be measured with a fancy oscilloscope. Close-in phase noise may be measured via TimePod or other specialized instrumentation. IIUC Mr. 08 has some of the equipment.
Regarding some of the other issues it looks like we are talking past each other. Different conceptual views and or different definitions/classifications are not necessarily wrong. Sometimes one view is more useful than the other depending on the problem at hand.
@jaddie, You are the first guy I know of to come along in this forum that understands as much as you do about audiometric testing, that and about human cognition, bias, etc. Its a welcome addition. However, as you probably know people do live in their own mentally constructed worlds. We are all better at seeing other's people's faults, imperfections, mistakes, etc., while virtually blind to seeing our own. Nobody is excepted. Please confirm if you have learned about that too.
Regarding some of the other issues it looks like we are talking past each other. Different conceptual views and or different definitions/classifications are not necessarily wrong. Sometimes one view is more useful than the other depending on the problem at hand.
@jaddie, You are the first guy I know of to come along in this forum that understands as much as you do about audiometric testing, that and about human cognition, bias, etc. Its a welcome addition. However, as you probably know people do live in their own mentally constructed worlds. We are all better at seeing other's people's faults, imperfections, mistakes, etc., while virtually blind to seeing our own. Nobody is excepted. Please confirm if you have learned about that too.
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Someone is working overtime. 🤨
Perhaps you can lead by example by confirming your own first?
No, it can't. You may be able to see it if you probe the right test point, but no quantification is possible with a scope.
Both can be evaluated with spectrum analysis, though quantification would be only relative. The problem is that you have to characterize the modulatiing signal to do that. Takes a calibrated discriminator.
I have learned that, but not here. I did come here to learn, and I have, just not what I expected.
Keysight Oscilloscope Jitter Measurement Package:
https://www.keysight.com/us/en/assets/7018-04304/data-sheets/5991-4061.pdf
Device sometimes use to evaluate dac clock close-in phase noise:
http://www.miles.io/timepod/ss_1pg.pdf
Phase noise measurement system:
https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=8848610
Phase noise effects in radar systems, including sidelobes of spectral peaks:
https://www.osti.gov/servlets/purl/1528837
https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=9384890
Attached below is a short excerpt on phase noise effects in dacs, including practical effects of close-in verses far-out phase noise.
EDIT: In case the ieee links timeout, please let me know. They are free access at the time of linking.
https://www.keysight.com/us/en/assets/7018-04304/data-sheets/5991-4061.pdf
Device sometimes use to evaluate dac clock close-in phase noise:
http://www.miles.io/timepod/ss_1pg.pdf
Phase noise measurement system:
https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=8848610
Phase noise effects in radar systems, including sidelobes of spectral peaks:
https://www.osti.gov/servlets/purl/1528837
https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=9384890
Attached below is a short excerpt on phase noise effects in dacs, including practical effects of close-in verses far-out phase noise.
EDIT: In case the ieee links timeout, please let me know. They are free access at the time of linking.
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please read carefully again: we start with the FM signal (sine carrier modulated by a low freq sine) and convert to AM by shifting the phases yielding an AM signal. The AM demodulated signal is of course a sine wave with harmonics (to reflect the infinity of side bands). The FM and AM signal are identical on a spectrum analyzer (same amplitude/power spectrum)
Some reference information regarding the perception of 'textures' which I spoke of previously in relation to learning how to detect low level distortion cues in chordal sounds: https://www.nature.com/articles/s41467-019-12893-0
Briefly, the existence of perceptual textures has been studied to some extent. Its possible role in distortion perception may not have been studied as of this time.
Briefly, the existence of perceptual textures has been studied to some extent. Its possible role in distortion perception may not have been studied as of this time.
Please also read again: Your spectrum does not show an AM signal modulated by a single frequency. Your time graph does.