Who would want a cable that attenuates portions of the audio spectrum
that they are trying to conduct from one component to another? That
means that if you hear a difference between two interconnects it’s
because the two cables in question are attenuating different parts of
the audio spectrum!
At a high level this is pretty true. And the unsaid argument (well, someone else above did say it) against expensive cables is that they simply cost too much given their contribution (or in deference to the above, lack of impairment). In optimizing ANYTHING, sound included, the question must always be "Can i spend this money elsewhere and get more benefit". I would say for $6k cables the answer is always yes. Most often on substantially better speakers (and $6k can buy quite an upgrade, unless you have IRSs or WAMMs or .....
But the above quote - and I'm being picky here -- is not quite technically correct. Cables can do more than attenuate frequencies. They can time-smear them - mostly via the dialectic (insulation). Just like in regular capacitors the linearity of the insulation varies greatly. Teflon (PTFE) and expanded polyprop and polyeth are about the best. Weird capacitive-inductive effects might also cause some overshoot and/or ringing, although I have never seen it on a scope. But we're being theoretical here, so lets include more proven theories.
Is this effect significant? Probably not very. Is it real and well understood? yes. We can also get diode effects from terminations (connectors).
In the grand scheme I find that there are awful cables, mostly pretty darm good ones, especially the ones i make myself, and some exotic ones that are both excellent and terrible. I suspect some of the terrible ones are attractive tone controls in some systems, like to tame the silly rising high end of many cartridges currently popular (yikes, holy screeech batman!)
G
