But to the subject at hand, okay, I accept the hypothesis that you can't measure cables traditionally to find a difference in sound. Then, observation should be used next. And the observed things are that the bass is tighter, or the midrange more full, or the highs are more airy. Those are things that can be measured. Why have we not done that? Null tests can prove those differences, So why haven't the cable manufactures themselves performed these experiments? Or published these results?
There is pretty much one answer that is obvious.
If I was making these things and found, possibly the worst amp, and it made a difference, then I would be using that to show the effect.
Would you prefer equipment that measures well or sounds better?
In the case of the power cable, I would like to see it test as being different.
We can also argue whether more distortion sound better, but in general I would strive for measuring well.
Maybe with the amplifier one can say, “Ok the front end is high fidelity and is neutral with low distortion,” and then consciously say… “I am going to now spice it up with a tube amp.”
If every piece of gear is spicing things up, and morning away from neutral fidelity, then it gets to be a recipe of chance, that could be hard to repeat.
In any case, as mentioned previously, we have no actual proof that anything is happening from the manufacturers… which seems odd.
I can take a preamp with a Stereophile published graph showing a minimum of 0.03 % THD+N and agonise whether going to a different one with 0.02% THD+N graph is worth the cost… but I have no way to understand what might happen with a power cable. It is just described with words.
As ANYONE, that has the slightest inkling of how the process works, knows: "...when science doesn't have an *ANSWER," it comes up with a, "THEORY".
*ie: To that other 96% of this universe, Science can't explain
I heard a quote the other day that described science as mostly “coming up with questions.” Then various hypothesis are investigated in order to describe what is happening and correlate the observations with reality. As the hypothesis are evolved, then we understand how things work, and can replicate/repeat these findings.
There may be a hypothesis as to why a cable might produce a change, but it needs to be repeated and measured to get to the point where the manufacturers can claim that they work, how they work, and when they may not work.
The hypothesis of crystal structure changes seems reasonable, but it would be more compelling with before and after microscope images showing that the crystals in fact changed.