You certainly are an audio politician. You basically admitted it to
@Phronesis a little while back. You often don't respond directly to questions or comments, rather you use them as a springboard to get on your soapbox and provide your talking points.
I'm afraid you misunderstood my comment. I said that I don't hit REPLY with people who have proven themselves to me to be either disingenuous or who refuse to argue logically and on point. When I hit reply in this board, it sends people a notification by email to come back and reply to my reply. If the person I'm speaking with is incapable of fair discourse the conversation just goes in circles. When I see a clear pattern of ad hominem attacks or argumentativeness or use of logical fallacies or complete refusal to support their points, I address the group with my replies, not the individual. It saves everyone's time and reduces clutter in the threads.
The problem I have with the long list of comparisons you say you've performed is the risk of expectation bias or confirmation bias.
I find that bias is much more likely to be a factor in sighted, uncontrolled tests of sounds that are very, very similar if not identical. That's the sort of claim we regularly hear around here. Here is an example of that...
"I bought my new DAC and played my favorite album and it was like a veil was lifted. The soundstage was three dimensional and I could feel the energy being conveyed by the musicians stronger. My old DAC can't compare." No level matching, not blind, no direct switching. Just an impression created by listening to music with no controls. Listening like that is fine for listening to music, and casual listening is the ultimate context we're aiming at, but testing like that leaves one wide open for bias and perceptual error.
I realize that my testing standards aren't up to what is expected from the AES, but I'm not looking for the same sorts of results. I know that there are measurable differences between DACs. I have no problem acknowledging that. Under extreme conditions, like using test tones or at very loud volume levels, those differences may even be barely audible. But I'm not looking for barely audible differences. I am looking for a clear difference that would affect my listening when I put on a CD of Beethoven or Prince or Sonny Rollins in my living room and sit down and listen to it for pleasure. I'm looking for a difference that matters.
A clear difference would show up in a test done with my controls. Bias can't make you confuse day and night. It can only influence you to mistake very similar things. If I level match and juggle the inputs and switch back and forth and I can't hear a difference, that is evidence enough for me that if a difference exists, it just doesn't matter in practice. My ears naturally compensate for very tiny differences. If I can't hear the difference in direct A/B switching, I'm never going to notice it when I sit down and listen to Beethoven's 9th from beginning to end. If you tell me that you have performed a level matched, direct A/B switched, blind comparison of two DACs yourself and heard clear differences, I will sit up and listen to you. That is exactly what I'm looking for- a DAC which sounds clearly different under moderate controls. I'd love to be able to verify that.
Performing level matched, direct A/B switched, blind comparison between two samples of the same music is more than enough to determine if a DAC is transparent for the purposes of listening to music casually in my home. I'm specifically looking for differences that are clearly audible under controlled conditions. If I can't detect a difference with controls, I'm never going to detect a difference without controls. My controls are actually a little into the range of overkill, but that is fine "just to be safe". Everyone has a certain amount of OCD. I just don't let it overwhelm my logical decision making process. I keep my eye on the prize... which is the natural sound of a symphony orchestra in my living room.
As I said before, I have a very precise equalization curve on my system. It's fine tuned to a dB or two across the entire spectrum to suit my listening room. If a piece of equipment is not transparent for the purposes of listening to music in the home, I don't want it, because I would have to apply corrections for each individual source. I'm not willing to do that. I need equipment that is audibly transparent for my purposes. Your purposes might be different... you may be testing for a recording studio or a mixing stage. That would require more stringent controls than I use. But my testing procedure is perfectly capable of determining transparency for the purposes of listening in the home.
One other thing I'll mention... When I see someone take my posts and reply to them line by line or phrase by phrase, I just read a sentence or two, then skip on by to the next person's post. It takes me way too long to parse out what they are talking about if they tear the context up into tiny little scraps and argue each little detail. My time is limited and I prefer to read clear paragraphs where someone states their case in the first sentence, supports it with with evidence in the next few sentences, then sums up with a conclusion at the end. Complete thoughts that are well organized get ideas across more effectively than scraps of contextless arguments piled up in a heap. I always try to reply that way myself.
There are other posters who don't mind line by line replies. You can feel free to communicate that way with them, but I don't have the patience for that particular argumentative technique. I apologize for not reading the last section of your post. If you want to reorganize it into a clearer format, I'd be happy to read it.
You often misstate the equivalence of measurement and recording.
I'm trying to think of a reason why it would be important for an audio component to be able to reproduce sound that isn't present in the recording. Maybe oversampling in DACs? But that is more of a processing thing than something that is measured as opposed to recorded. Do you have any examples of that? Perhaps I misunderstand the point you are making.
Personally, I don't see any reason for audio equipment to need to reproduce sound human ears can't hear. Audibly perfect is good enough. I suppose their can be psychological reasons why someone would feel the need to control things they can't physically perceive, but I'm reasonably well balanced and practical. It isn't a problem for me.
I don't see how small differences in frequency response could even potentially account for perception of differences like bigger stage, more precise imaging, better instrument separation, more articulate bass, much more detail, etc. There would either need to be something else besides frequency response
Aha! That is PRECISELY where bias rears its ugly head! People who do controlled tests generally are unable to consistently detect differences like "imaging" and all those other vague things you mention. If you see someone using words like that, you can pretty much be assured that they haven't taken steps to eliminate bias from their comparison. Here in sound science those sorts of things are big red flags that make us ask politely about what sort of controls the person applied to their comparison test.