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Old 14th July 2019, 09:09 PM   #271
jan.didden is offline jan.didden  Europe
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OK, so then can we find a method of determining equipment reproduction fidelity that is objective, not depending on the person who does the determining?

Jan
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Old 15th July 2019, 12:23 AM   #272
Ken Newton is offline Ken Newton  United States
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Originally Posted by jan.didden View Post
OK, so then can we find a method of determining equipment reproduction fidelity that is objective, not depending on the person who does the determining?

Jan
Jan, I'm uncertain. Of course, objective determination is inherently instrumented determination, which is what we have now. If you are asking me about an objective measurement of subjective perception, then I don't know that we will find a solid method. Part of the problem would be determining a way to quantify subjective perception. To accurately communicate it, particularly to consumers. Right now, we only have the flowery prose of most hifi magazine reviews to guide us on this matter. Perhaps, one day, there will be an instrument which accurately predicts the subjective listening experience. I know, you'd say that your test bench is full of such instruments.

I'm no expert on double blind-testing, nor a statistician, however, double-blind testing is probably the closest thing we have to an scientific method for testing subjective human perception. I have always wondered about one issue when seeing test results from a group of subjects. Depending on the nature of the questions, there can be a normal statistical distribution of results. A normal distribution has variance. A variance in subject test response could also signal an actual variance in subject perception.

Indeed, it may indicate that not EVERY test subject perceived exactly the same thing, or did not perceive it to exactly the same degree. The temptation is to dismiss such outlier data points as false, but they are not necessarily false. Such variances are eaily computed into a standard deviation which, assuming the distribution is normal, can then be used to establish a confidence figure for any given data point. However, a figure of low confidence isn't a figure of zero confidence.

It seems possible that some of the test subjects actually had a true difference in perception? I suppose, one way to remove that question would be to test the entire group multiple times, and look for positive correlations in the data points of outlier test subject responses across the many tests. I don't know.

Last edited by Ken Newton; 15th July 2019 at 12:42 AM.
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Old 15th July 2019, 06:17 AM   #273
jan.didden is offline jan.didden  Europe
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Can't say I disagree with the gist of your post. But maybe we must accept that personal preferences are just that, and not necessarily any indication of reproduction accuracy. As long as some people swear by single-ended tubes, or massive class A, or optimally-biased class B, or hybrid amps, all with different degrees of accuracy, maybe we have to conclude that audio is a fashion industry and there's a market for anything.

That would mean that in the design process you need to accurately identify what aspects of sound reproduction are desired by your target market, and design accordingly, not necessarily for maximum transparency. Something Nelson Pass, to name just one, is extremely good at.

You also see it in this diy world, anything goes, and it is always touted as the worlds' best sound. Which is a logical fallacy because my amps are the worlds' best

Jan
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Old 15th July 2019, 06:49 AM   #274
chris719 is offline chris719  United States
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Ken, I think it's hard to draw a line and say that something is inaudible overkill unless you want to take a hard-line approach and say that everything "decent" sounds the same. That's fine (and that's probably where I am at here), but we have people in some threads saying that phone DACs sound fine, and some in others complaining about -100 dBc phase noise at 10 Hz offset and other phenomena barely measurable.

For every person that thinks they know what makes good sounding electronics, there are a bunch people who prefer the exact opposite. This is what bothers me from a logical standpoint about "subjectivists" that start to claim measurement x or y are irrelevant. You can pick a measurement (THD, IMD, jitter, etc.) and I can go find you people who disagree from this forum in about 5 minutes.

For that reason, I think it's best to appreciate technical posts for what they are and not necessarily from an audibility point of view. It's a slippery slope and a lot of people seem to have opinions that do not align with others.
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Old 16th July 2019, 02:08 AM   #275
Ken Newton is offline Ken Newton  United States
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Originally Posted by jan.didden View Post
That would mean that in the design process you need to accurately identify what aspects of sound reproduction are desired by your target market, and design accordingly, not necessarily for maximum transparency. Something Nelson Pass, to name just one, is extremely good at.

Jan
This is where commercial high-end gear is most intriguing for me from a technical perspective. Designing to the subjective desires of a target market still requires the designer to translate those subjective desires into a set of objective engineering parameters. Knowledge of exactly which parameters then are key, and how to engineer them to obtain the desired subjective result, is the trick for which many dollars are paid by high-end customers.
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Old 16th July 2019, 03:10 AM   #276
DPH is offline DPH  United States
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That presumes they're audibly different in a way that appears obscure to rigorous instrumented tests. Way too many transistors have flipped states over the sound vs measurements debate...

*Excepting those designs which aim for distortions, whether harmonic or in amplitude/frequency response.
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Last edited by DPH; 16th July 2019 at 03:21 AM.
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Old 16th July 2019, 03:14 AM   #277
Ken Newton is offline Ken Newton  United States
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Originally Posted by chris719 View Post
...but we have people in some threads saying that phone DACs sound fine, and some in others complaining about -100 dBc phase noise at 10 Hz offset and other phenomena barely measurable.
Chris, I've always suspected that many reports of differing perceptions aren't truly that, but are actually differences in auditory observational skills. Such skills are developed by long experience simply listening to hifi music reproduction systems. Perhaps, notions that iPhones are hifi, and that close-in phase noise is audible, is a dichotomy of perception explainable by differences in listener observational skills/experience.

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For every person that thinks they know what makes good sounding electronics, there are a bunch people who prefer the exact opposite. This is what bothers me from a logical standpoint about "subjectivists" that start to claim measurement x or y are irrelevant. You can pick a measurement (THD, IMD, jitter, etc.) and I can go find you people who disagree from this forum in about 5 minutes.
I essentially agree with your observation. I suspect that the number of people in command of the technical formula to repeatedly obtain audio gear which produces some particular, subjectively desirable sonic template are relatively few. There are many supposed experts around. Since objective perfection (as far as human perceptual limits are concerned) can be found even among mass-market gear, so, it would seem logical that 'desirable' subjective high-end sonics are to be found then in some particular combination of objective imperfections.

Perhaps, that is not only logical, but also true. However, I'm having difficulty in accepting that we can essentially have widespread objective technical perfection, yet rarely do I hear playback which subjectively sounds convincingly like real or live music. Often, far from it. Why is this? Perhaps, there is not enough focus on the dynamic interaction of certain technical parameters. Or, perhaps, we are simply being too limited by our current 2-channel stereo playback paradigm, dominant since the late 50's. I'm sure Ambisonics fans are raising their hands.
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Old 16th July 2019, 03:28 AM   #278
chris719 is offline chris719  United States
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Originally Posted by Ken Newton View Post
Chris, I've always suspected that many reports of differing perceptions aren't truly that, but are actually differences in auditory observational skills. Such skills are developed by long experience simply listening to hifi music reproduction systems. Perhaps, notions that iPhones are hifi, and that close-in phase noise is audible, is a dichotomy of perception explainable by differences in listener observational skills/experience.



I essentially agree with your observation. I suspect that the number of people in command of the technical formula to repeatedly obtain audio gear which produces some particular, subjectively desirable sonic template are relatively few. There are many supposed experts around. Since objective perfection (as far as human perceptual limits are concerned) can be found even among mass-market gear, so, it would seem logical that 'desirable' subjective high-end sonics are to be found then in some particular combination of objective imperfections.

Perhaps, that is not only logical, but also true. However, I'm having difficulty in accepting that we can essentially have widespread objective technical perfection, yet rarely do I hear playback which subjectively sounds convincingly like real or live music. Often, far from it. Why is this? Perhaps, there is not enough focus on the dynamic interaction of certain technical parameters. Or, perhaps, we are simply being too limited by our current 2-channel stereo playback paradigm, dominant since the late 50's. I'm sure Ambisonics fans are raising their hands.
At risk of derailing the thread further...

I do tend to think the stereo paradigm and speakers + room interactions are much more limiting than the electronics. I haven't heard Ambisonics or the SVS Realiser, but I find binaural recordings on good headphones to be a much improved experience.

In terms of this composite op-amp, it's really not too expensive to build. For a good number of diyers I would actually think their own time costs more than the BOM on many projects.
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Old 16th July 2019, 03:35 AM   #279
Ken Newton is offline Ken Newton  United States
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Originally Posted by chris719 View Post
...In terms of this composite op-amp, it's really not too expensive to build.
Agreed. I'm going forward with incorporating it in to the analog section of an experimental DAC I'm designing.
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Old 1st August 2019, 11:07 PM   #280
dattorro is offline dattorro
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Agreed. I'm going forward with incorporating it in to the analog section of an experimental DAC I'm designing.
Can you tell us more about the DAC?
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