Originally Posted by Heidegger
Evidence, shmevidence ~ the proof is in the eating. If Nick comes out and tells me that there can objectively be no difference between my headphone chords, then I would immediately know that I can't trust a thing he says, no matter how many facts and figures and graphs and charts and bells and whistles he backs it up with.
Long story short, I once worked at a TV station whose lab was one of several selected for HDTV research in the late 80s. As it happened their part of the job was quickly completed, with the result that lots of talented and expensive engineers had nothing to do for the balance of the year. Except that engineers always find something to do, and in this case they started a project to measure differences between samples of delivered equipment. (Probably a management initiative to get money back.) With super-precise standards, they found objective differences between everything. Cable A measured differently than cable B. Today's sample of cable C measured differently than yesterday's sample. (These were wide-bandwidth video cables, not that it matters.) But the differences were incredibly tiny, and were absolutely dwarfed by the differences between samples of more complex items.
So my direct, personal, learned experience is that yes, there will be objective differences between cables. There will not be subjective differences, even if you're Superman. And - given the data - it makes absolutely no sense at all to A/B cables instead of A/Bing a Thursday sample of your favorite can against a Friday sample. The transducer data (on Tannoy Little Red Monitors, if you're interested) showed literally hundreds of thousands of times greater dissimilarity between samples with adjacent serial numbers than between all the cables in the world.
So all this angst and energy would be far better spent A/Bing different headphone samples (or amps, or practically anything) than cables. It's totally dumb to stick with the headphone that came in the mail and swap its cable ten times. Spend your time hiking back and forth to the post office, returning nine headphones to the dealer. The benefit in SQ will make you forget cables in a big hurry.