I performed another test — what changed from last time:
- 2 runs of each (1x copper, 1x silver, 1x copper, 1x silver)
- Installed foam windscreen on mic
- Pushed mic into headphone, aligned headphone cup to be perpendicular to mic
- Increased amp volume to 0.0dB
I did not get the peaks this time, perhaps as a result of the windscreen on the mic, but the increased low-mid bass is very clear, as well as a slight drop-off in upper treble.
We're getting somewhere, the acoustic abyss in the treble on the first graph isn't showing up on this one(having one somewhere else would have led to the same conclusion that the cable had nothing to do with it). Several of us were already pretty sure a cable didn't have(and certainly shouldn't be sold if they did) the ability to create that anyway, but now the last graph suggests that the laws of physics probably stand when it comes to this specific detail. That's already a step in the right direction. Half the "clear" evidence is gone with just another run of measurement. That's the type of stuff we do often get with measurement methods that are less than ideally controlled and why I insisted on trying not to move the headphone, which I fully recognize as easier said than done.
It's another one of those "we do this not because it is easy, but because we thought it would be easy".
About refusing to believe, I can't talk for others, but I've done my fair share of amateurish measurements, and as I said, while I'm actually onboard with the possibility of audible difference from cable swap under particular conditions or at least one extremely weird and bad cable, what you've showed us didn't match my most likely expectations for FR variations caused by cables. And when
@FunkyBassMan brought up the massive treble dip as evidence, my immediate thought wasn't that I was a "non-believer". It was that he had little understanding about electrical stuff.
I don't have any silver cable, so I can't test that. I have no plan to get some, because my own experience with silver cables has been one of regret. Ironically, I have silver for soldering jobs (to try lead-free options as I'm making cables at my desk in the bedroom... not great, not terrible), and soldering wires with silver is a freaking PITA to use.
This is obviously just some random and insignificant stories and for all you know I'm a werewolf with an agenda. But I hope it's enough to explain why, even though I have some cheap amateur tools for measurements, I have nothing to show for silver vs copper cables. If we get into the sound of silver vs stainless steel spoons, then I might be able to participate more actively.
Mind sharing the 2 series of REW measurements with me, and whatever else you might decide to get? If the files are too heavy, forget it, it's just so I can fool around for visibility's sake.