The most obvious rebuttal to objectivism is just that amplifiers are bulit for listening, and all that matters in the end is the subjective perception of the listener.
Yes, and it is what a blind test measures (there are even used in psychology, after all). This is one of the things that bothers me most, why do publicized blind tests show a spectacular failure of distinguishing between amplifiers? Likewise for the subtraction tests -- if you can't hear a residue, then how could there be audible distortion? There simply is no rational argument against blind testing. Some argue that a nil result doesn't prove there is no difference, which is true, but statistically over a number of trials the likelihood that there is a difference can become vanishingly small.
Yes, I've seen this before, but not heard much discussion about it.
We can nevertheless perform a myriad of feats that not even the best microphones and DSP algorithms can match...like picking a voice we recognize out of a room full of people.
Part of that trick has to do with directionality. It's much much harder to do with a mono signal. The rest of the process is indeed DSP, although implemented in wetware instead of silicon.
Also relevant is the fact (which I unfortuneately know only from anecdotes) that a difference in volume that's not directly perceptible will nonetheless make a louder amplifier sound better.
Yes, it is very important in blind tests that levels are properly matched. But if just a slight difference in volume can mask other issues, doesn't that make them insignificant?
One thing that Self left out is the issue of imaging. The ear can distinguish clicks as separate even if they are at a rate above 20 kHz.
The only rational objection I came up with regarding this article was his discussion of phase. Apparently he is unaware that phase is an important component of directional perception; though, on the other hand, with most speaker setups it's already messed up enough so that the amplifier is the least offender in that respect.
Also, on the Crossover Design page (
http://www.silcom.com/~aludwig/Sysde...ove_Design.htm ), it is mentioned that ears can still hear clicks occuring at a rate faster than 20 kHz as distinct (in the Transient Response section of the page, though the server is down at the time of writing, but you can use the Google cache). Which leaves me wondering whether amplifier blind tests would have more positive results in a setup where phase distortion from the speakers and room reflections are eliminated (that still leaves crosstalk to mess up the imaging, however, so using headphones with a binaural recording would be better, even though headphones do not present a realistic load to a power amp).