"Things that cannot be measured"

[raistlin65]

I completely agree that there is no audible difference in (properly functioning) amps and dac’s. Where I differ on opinion is the emotions attached to gear and the enjoyment that can be gained from it. My question is what’s wrong with buying nice expensive gear that you like the aesthetics of and gaining enjoyment, at least for me the music itself is only part of it. I would also say that most left brainers here on ASR are also experiencing a placebo effect from your simple signal pathways and extremely clean amps, the research and knowledge of the science behind it adds to your emotional enjoyment of your music.

Audio science doesn't say anything about you can't indulge in perceptual bias. So why not?

It's denying the influences of perceptual bias that is the issue.

Many audiophiles are like the guy who goes into a strip club, and then actually believes all of the women want to go home with him because of the way he's being treated. An objectivist can recognize it's a fantasy and still enjoy it.

 

[Sawdust123]

Also, when testing with an AP analyzer you usually monitor the distortion residual acoustically and any glitching etc will expose itself readily.

It depends what vintage AP gear. The older System 1, System 2 and 2700 series had a an analog circuit to listen to the distortion residual. The APx series let's you view or listen to the residual as well (albeit with some latency). However, the APx doesn't take continuous readings. There are dead spots between samples so it is quite possible to miss certain anomalies.

 

[rdenney]

I'm reminded yet again of the Stereophile Challenge, which was successfully met by Bob Carver. He had a hotel room, test equipment, and electronic components available to him, and in 72 hours, revised the hardware of an amp to match the sound signature of a very different amp. This was before DSP, of course. What did he do? He use null testing to reveal (sonically) the differences between the amps, and then fiddled with components until the differences were reduced to a level below (as I recall) -60 dB. At that point, the expert judges could not subjectively distinguish between the amps (at -30 dB they could).

Note the most important aspect of this that is not mentioned: Carver's objective was not absolute linearity, but rather to match the non-linear behavior of one amp to the non-linear behavior of another amp under the same operating conditions. The target amp had been subjectively judged to be superb, but I take that to mean it had a subtle coloration that was pleasing to their ears.

Is there anything that Carver heard in that null test that could not be measured? Of course not. If his only tool for eliminating the difference was changing the values of specific components, the result must clearly be measurable. Play that null difference into test equipment, and everything about the differences would result in squiggles of either frequency, phase, or amplitude.

In one of those RMAF Youtube videos, John Atkinson was asked what made a good amp, and his response was a healthy measure of even-order harmonic distortion. He had his tongue in his cheek, of course, but not all the way. I suspect the fellow from Yamaha was "tuning" his amp to sound good by that sort of measure, not necessarily to be absolutely transparent.

The problem is with the shibboleths that are subsequently added or edited by the marketers. They will show design specs rather than test results, and claim linearity when their designer's real objective is not necessarily absolute linearity.

Rick "for whom 'musical' means that instruments sound like themselves, and a high second-harmonic might be pleasing but can violate that objective" Denney

 

[Sgt. Ear Ache]

In one of those RMAF Youtube videos, John Atkinson was asked what made a good amp, and his response was a healthy measure of even-order harmonic distortion. He had his tongue in his cheek, of course, but not all the way. I suspect the fellow from Yamaha was "tuning" his amp to sound good by that sort of measure, not necessarily to be absolutely transparent.

which is exactly the critical point - the tuning difference is not some unmeasurable mystery factor...whatever tuning was done to achieve extra "musicality," (assuming anything was actually done and it's not just marketing giffle-gab) it's a thing that will be readily apparent in measurements.

 

[rdenney]

Emotion can be heard. And I’m not talking about the emotional connection m between the listener and the program. The emotion I speak of is what separates a good piano performance to a great one.

Go to your local opera or orchestra sometime. Nothing in that venue can be measured by a machine...

Is it the job of the audio equipment to inject something on top of that performance, or to as faithfully as possible convey it to the home listener?

Rick "wondering if audio manufacturers get paid royalties for artistic creation" Denney

 

[rdenney]

which is exactly the critical point - the tuning difference is not some unmeasurable mystery factor...whatever tuning was done to achieve extra "musicality," (assuming anything was actually done and it's not just marketing giffle-gab) it's a thing that will be readily apparent in measurements.

Yes, but the argument about measurability is a red herring. It's covering up what seems apparent to me: Not all manufacturers have the objective of absolute linearity, no matter what their ad copy claims.

Rick "thinking argument about tactics (like measurements) are meaningless without clarity of objectives" Denney

 

[Sawdust123]

In one of those RMAF Youtube videos, John Atkinson was asked what made a good amp, and his response was a healthy measure of even-order harmonic distortion. He had his tongue in his cheek, of course, but not all the way.

One of my former customers was in the business of modeling old studio gear and create custom plug-ins for DAWs used by recording engineers. We had a nice long talk and discussed the issues faced modeling 40+ year old tube design when every surviving sample has been drifting in different directions all these years and had numerous components replaced. He related the story of one of their emulators failing acceptance from their critical reviewers. They double checked their transfer function and it was fine. They also double checked their measurements used to determine the transfer function and those too were fine. The only thing missing from their emulation was the noise and hum of the original circuitry. They then added that back into the algorithm and lo and behold, their critical reviewers finally approved the emulator.

 

[Sgt. Ear Ache]

Yes, but the argument about measurability is a red herring. It's covering up what seems apparent to me: Not all manufacturers have the objective of absolute linearity, no matter what their ad copy claims.

Rick "thinking argument about tactics (like measurements) are meaningless without clarity of objectives" Denney

It's not a red herring in this thread which is specifically floating the notion that there might be some unmeasurable element we are missing...

Nobody anywhere has claimed that the objective of absolute linearity is universal. (even if some of us think it probably should be)

 

[rdenney]

It's not a red herring in this thread which is specifically floating the notion that there might be some unmeasurable element we are missing...

Nobody anywhere has claimed that the objective of absolute linearity is universal. (even if some of us think it probably should be)

I was arguing against the notion of the thread. It allows these two religious camps, in which each camp's true theologians might agree if the discussion were centered around objectives, but the followers, not seeing the differences of theology, argue about differences in religious practice to no good end.

Rick "not bound by the OP's construct" Denney

 

[Sgt. Ear Ache]

I was arguing against the notion of the thread. It allows these two religious camps, in which each camp's true theologians might agree if the discussion were centered around objectives, but the followers, not seeing the differences of theology, argue about differences in religious practice to no good end.

Rick "not bound by the OP's construct" Denney

I get where you're coming from, but there isn't that much debate about the non-linear things. If something has a 2 or 3 db boost from 2-8khz, it might sound different from something that doesn't. The debates arise when we have 2 things (dacs for instance) that seem to basically measure the same within some reasonable degree of audibility, but claims are made that one of the things sounds "more musical," "warmer," "more open," or any number of other audiophile buzzwords than the other...due to some mystical unknown element that science has yet to identify.

 

[rdenney]

True enough. That's where I fall back on having to demonstrate that the perception is repeatable and consistent, and only then has one earned the right to question measurement methods.

Rick "who wonders, however, if a transfer function of 100% was the objective even for DACs, before careful measurement protocols became widely published" Denney

 

[scott wurcer]

BTW, Bruce was a big fan of Analog Devices until they announced the discontinuance of a matched pair of BJTs that AP used a lot of (forget the model). Apparently the announcement was made after the foundry shut down the process leaving no chance for large last time buys. He vowed at the time to design out all AD devices in all AP gear and never do business with them again. If I recall correctly AD later reconsidered their decision.

We have our own fabs for bi-polar (well for me "had" since I've been retired for years). THAT Corp. has had equivalent drop in devices for years.

 

[rdenney]

By the way, we should distinguish between "I hear a difference" and "Any sophisticated and experienced audiophile with an appropriately transparent system will hear a difference."

The emotion of the performance gets to play a role in the first one, and even one's multi-sensory perception of the total listening experience (including what they see, and even what they paid). As soon as we imply that it is transferrable to others, we have something additional to prove--that others will perceive it, even if they do not value what they see or pay for the same way. And the second statement, even if implied, plays on a subversive emotion to be perceived as an expert, or to be associated with celebrities.

Rick "'you would share my preference if you were as good as me'" Denney

 

[Wes]

before TTD happens (Total Thread Divergence), how long did we have to wait to get the first F added to FT?

- which is when it became a worthwhile technique...

 

[scott wurcer]

before TTD happens (Total Thread Divergence), how long did we have to wait to get the first F added to FT?

- which is when it became a worthwhile technique...

Gauss did one in 1805, BTW it is estimated that Gauss had the highest IQ in history (how they make this claim, I don't know). I have a friend that built a hardware FFT out of discrete TTL based on Cooley and Tuckey a year after they published their algorithm (1968). It was his PhD thesis.

 

[Wes]

Right, so the FFT Dark Ages lasted ~~1.6 centuries

 

[Lambda]

Not relay FFT or FR but some how related

 

[palmoyas]

Someone just dropped this argument on me when trying to justify speaker break-in without any data or evidence:

"We do not know how to measure yet and, therefore, it would be more appropriate to say: our current forms of measurement have not caught up with ability of the brain to discern changes. And that still might take a while."

 

[Doodski]

Someone just dropped this argument on me when trying to justify speaker break-in without any data or evidence:

"We do not know how to measure yet and, therefore, it would be more appropriate to say: our current forms of measurement have not caught up with ability of the brain to discern changes. And that still might take a while."

Some people simply fantasize about metrology when they have absolutely no idea about what it entails.

 

[Sgt. Ear Ache]

Someone just dropped this argument on me when trying to justify speaker break-in without any data or evidence:

"We do not know how to measure yet and, therefore, it would be more appropriate to say: our current forms of measurement have not caught up with ability of the brain to discern changes. And that still might take a while."

I mean...what can you really say about this stuff. Its so silly