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Benchmark AHB2 / Class D Purifi Eigentakt / Mark Levinson 333 - Listening impression & Conclusion

Blaspheme

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That is correct, but with these you are probably a bit closer to the truth.
Of course, if I had an AP box lying around I'd totally plug that shit in and give it a whirl. I'd be curious. So ...

EdiT: the challenge would be whether you could use test parameters like roughness, impulsiveness, sharpness or other percentiles to detect different behaviour in amplifiers (say) that had audible consequences, or explained subjective hearing impressions.
 
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rdenney

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Of course, if I had an AP box lying around I'd totally plug that shit in and give it a whirl. I'd be curious. So ...

EdiT: the challenge would be whether you could use test parameters like roughness, impulsiveness, sharpness or other percentiles to detect different behaviour in amplifiers (say) that had audible consequences, or explained subjective hearing impressions.

The challenge is in understanding how those adjectives can be influenced by actual sound characteristics. That is a psycho-acoustic question. What mix of distortions (in the general sense) influence people in a way that calls those adjectives to mind?

Connecting equipment measurements to such impressions must go through that psycho-acoustic understanding.

As a first step, however, those impressions have to be traced to real perceptions, not simply claims that evaporate when knowledge of what equipment is in use is removed. Otherwise, every charlatan that comes along can demand that such tests be conducted all over again, and when experts are unwilling to do so, use that unwillingness to validate their claims. Such behavior exists because of a credulous pool of enthusiasts, some of whom are good with adjectives, motivated by the desire to be seen as exceptionally discerning.

It is relatively easy to weed out false claims first using controlled perception testing.

The line between the charlatans and the merely credulous is not easy to discern.

The problem with such adjectives in the absence of that rigor is that they sound desirable without actually meaning anything.

Rick “journalism once eschewed adjectives” Denney
 

Blaspheme

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The challenge is in understanding how those adjectives can be influenced by actual sound characteristics. That is a psycho-acoustic question. What mix of distortions (in the general sense) influence people in a way that calls those adjectives to mind?

Connecting equipment measurements to such impressions must go through that psycho-acoustic understanding.

As a first step, however, those impressions have to be traced to real perceptions, not simply claims that evaporate when knowledge of what equipment is in use is removed. Otherwise, every charlatan that comes along can demand that such tests be conducted all over again, and when experts are unwilling to do so, use that unwillingness to validate their claims. Such behavior exists because of a credulous pool of enthusiasts, some of whom are good with adjectives, motivated by the desire to be seen as exceptionally discerning.

It is relatively easy to weed out false claims first using controlled perception testing.

The line between the charlatans and the merely credulous is not easy to discern.

The problem with such adjectives in the absence of that rigor is that they sound desirable without actually meaning anything.

Rick “journalism once eschewed adjectives” Denney
Yes, I'm assuming both doing both what I mention in post #221 above (with you quote in part) and what I suggest previously at post #217. And I'm assuming rigour. There's no point otherwise. The rest is blather (or from another perspective, politics).
 

rdenney

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Yes, I'm assuming both doing both what I mention in post #221 above (with you quote in part) and what I suggest previously at post #217. And I'm assuming rigour. There's no point otherwise. The rest is blather (or from another perspective, politics).

But the steps in the process I suggest would be:

1. Identify an amp thought to be, say, “impulsive”.

2. Identify an alternative amp thought not to be “impulsive”.

3. Identify a control amp of unknown impulsiveness

4. Set up a controlled comparison that exactly matches levels, and that keeps all amps in their specified operational range.

5. It may turn out that the adjectives emerge from clipping behavior, which might suggest an alternative setup. For that, I would record the sound of the amp through reference speakers in a way that is exactly similar for all amps, and the play back the recordings in a level-matched ABX test. The amps would be overdriven to clipping some carefully controlled percentage of the time, say 1%. Arguments would ensue about the choice of reference speakers, the recording methodology, the recording medium, and the phase of the Moon, of course.

6. Determine that perceived differences in amps are statistically valid when compared blind.

7. Only then can one attempt to correlate perceived differences with what one might see on an AP analyzer.

Rick “always suspecting that clipping behavior contributes to these impression” Denney
 

Gorgonzola

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Tools are one thing, curiosity and meta-cognitive abilities are another.
I've been avoiding this thread for a while because it is futile, IMO, to argue with the hardcore objectivists -- every bit as it is with hardcore subjectivists.

My original question to objectivists is whether they hear a difference between amplifiers, (say if they happen to be hearing a new one in their familiar system for whatever reason) -- this assumes that they have done neither measurements nor ABX testing before listening.
  • If they do, well, what is the source of their bias? Most would say they aren't influence by appearance, reputation, or price.
  • If they don't hear any difference, then that could very well be confirmation bias, right?
 

Gregss

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I've been avoiding this thread for a while because it is futile, IMO, to argue with the hardcore objectivists -- every bit as it is with hardcore subjectivists.

My original question to objectivists is whether they hear a difference between amplifiers, (say if they happen to be hearing a new one in their familiar system for whatever reason) -- this assumes that they have done neither measurements nor ABX testing before listening.
  • If they do, well, what is the source of their bias? Most would say they aren't influence by appearance, reputation, or price.
  • If they don't hear any difference, then that could very well be confirmation bias, right?

EXACTLY why blind testing is needed. Then you don't have to guess if any bias or expectations are influencing impressions.
 

LightninBoy

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  • If they do, well, what is the source of their bias? Most would say they aren't influence by appearance, reputation, or price.

The premise of this question is false. Most objectivist (I would say "all" if they are truly objectivist) know they are influenced by such things.

  • If they don't hear any difference, then that could very well be confirmation bias, right?

Yes.
 

Mart68

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I've been avoiding this thread for a while because it is futile, IMO, to argue with the hardcore objectivists -- every bit as it is with hardcore subjectivists.
  • If they do, well, what is the source of their bias? Most would say they aren't influence by appearance, reputation, or price.
  • If they don't hear any difference, then that could very well be confirmation bias, right?

No, from this and other posts I get the idea that you don't get how unconscious bias works.

The key bit is that it is 'unconscious.' We are not aware it is happening and we have no control over it. It doesn't matter what one chooses to label oneself, or what conscious expectations you have going in.

You can't decide not to be unconsciously influenced by any factors you have conscious knowledge of, including appearance, reputation or price, and it's impossible to say how they are going to influence your perception.

You expect to hear an improvement, instead it sounds worse. You expect to hear it sound worse, instead it sounds better. That's happened to all of us many times. None of these perceptions are reliable without controls.
 

rdenney

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I've been avoiding this thread for a while because it is futile, IMO, to argue with the hardcore objectivists -- every bit as it is with hardcore subjectivists.

My original question to objectivists is whether they hear a difference between amplifiers, (say if they happen to be hearing a new one in their familiar system for whatever reason) -- this assumes that they have done neither measurements nor ABX testing before listening.
  • If they do, well, what is the source of their bias? Most would say they aren't influence by appearance, reputation, or price.
  • If they don't hear any difference, then that could very well be confirmation bias, right?
Your first assumption is invalid. It is a myth that we actually know our expectations, or to what extent our unconscious expectations may dominate over our conscious expectations.

If we don’t hear a difference, and that corresponds to measured effects, then claiming a difference requires something additionally persuasive.

If we do hear a difference, and that difference is explained or indicated by measurements, then claiming no difference requires something additionally persuasive.

If what we hear contradicts what we measure, then it seems to me that we have the burden of first demonstrating that we can hear it consistently in a controlled test.

Rick “instead of discrediting measurements in order to further delusional or dishonest claims” Denney
 

Wes

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I just want to know what "meta-cognitive" means
 

Blaspheme

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I just want to know what "meta-cognitive" means
1. select the text "meta-cognitive"
2. two-finger tap on the trackpad
3. select 'Look up "meta-cognitive"'
4. voila!
 

Blaspheme

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But the steps in the process I suggest would be:

1. Identify an amp thought to be, say, “impulsive”.

2. Identify an alternative amp thought not to be “impulsive”.

3. Identify a control amp of unknown impulsiveness

4. Set up a controlled comparison that exactly matches levels, and that keeps all amps in their specified operational range.

5. It may turn out that the adjectives emerge from clipping behavior, which might suggest an alternative setup. For that, I would record the sound of the amp through reference speakers in a way that is exactly similar for all amps, and the play back the recordings in a level-matched ABX test. The amps would be overdriven to clipping some carefully controlled percentage of the time, say 1%. Arguments would ensue about the choice of reference speakers, the recording methodology, the recording medium, and the phase of the Moon, of course.

6. Determine that perceived differences in amps are statistically valid when compared blind.

7. Only then can one attempt to correlate perceived differences with what one might see on an AP analyzer.

Rick “always suspecting that clipping behavior contributes to these impression” Denney
I like the list, and the approach in general.

Reading your previous posts, I though you were referring to the whole gamut of subjectivist descriptors—à la the Stereophile glossary—but the same process is likely applicable. By my reading 'impulsiveness' is a characteristic of the signal in the first instance. We'd be interested in whether amp A rendered it differently to amp B.

I'd do some exploratory listening and measuring to find out whether difference in rendering of 'impulsiveness' (say) by amps was either subjectively discernible or objectively measurable at all. And so on for other potentially interesting metrics.

I'd also examine the blind experiment methodology to establish adequate sensitivity to the subject. We don't want to rely on a method that merely confirms 'hardcore objectivist' biases via type 2 errors.

Then I'd do something along the lines of what you suggest.
 
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Blaspheme

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I've been avoiding this thread for a while because it is futile, IMO, to argue with the hardcore objectivists -- every bit as it is with hardcore subjectivists. ...
I'm aware of the likely futility of my recent posts in that respect. I was going to suggest ignoring hard-liners of any stripe—which only encourages them—but chose brevity.

Edit: so I'm uninterested here in religious (or other) conversion, just in different lines of inquiry.
 
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MasterApex

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Does anyone do measurement of crest factor (segment at 50min) on this video that explains why amplifiers sound different

 

restorer-john

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Does anyone do measurement of crest factor (segment at 50min) on this video that explains why amplifiers sound different

What is so frustrating is that proper reviewers and audio testers ran tests like this in the 1970s.

They all knew amplifiers sounded different up and around their maximum power. And also particularly what happened when overloaded with transients. None of this is new. And yet an entire generation of "reviewers" seems to think they are re-inventing the wheel. :facepalm:

Overload recovery is pretty much the biggest differentiator of why similarly rated amplifiers sound vastly different when operating at high powers. It is especially true with high dynamic range music, orchestral and jazz climaxes etc.

See this post:
https://www.audiosciencereview.com/...integrated-amplifier.20657/page-4#post-734675

Good overload recovery:
1623630212419.png

Poor overload recovery:
1623630117169.png
 
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