I had a friend whose system literally gave me a headache. I mean leaving his house one night my head literally ached. It was very hard sitting there listening to it to say exactly what was wrong. All I knew was every time I was there I wanted to turn the volume down. Whatever it was, it was too loud. This was years ago, back when grain and glare and listener fatigue were just words on a page not yet that well established with real live experience. So I guess always something there to be learned if you're willing.
One time he bought this sweet pre-amp, by Tim Paravicini I think. Suddenly I wanted to turn the volume up! It sounded a whole lot better. More engaging. Involving. Where it had been off-putting and fatiguing now it was drawing you in.
But this guy, he was always tinkering. By the next visit he had somehow tinkered it back to the same sterile off-putting fatigue-inducing presentation.
The few times he came over to hear my system he studiously avoided anything outright critical yet always managed to make clear his disdain for what I'm sure he regarded as overly warm if not euphonic.
Like I said he was always tinkering. One time he brings over the best DIY interconnect he ever made. In his system it sounded exactly as good as the $5k IC it was copied from. He was dead sure of it. Could not hear any difference. In his system.
In mine it was night and day. Easy as pie to hear the difference. They were nowhere near the same. There was no denying it. He heard it too. Not only that, but the one he had made, we compared it to the cheapest/oldest I could pull from my old cable drawer, and it wasn't even as good as that! He could hear it. Clear as day. Which he absolutely could not in his system.
Pretty obviously one system is a whole lot more resolving and revealing than another. Equally obviously its possible to be totally confused about this, even to the point of getting it completely backwards and upside down.
The thing is, this guy was really happy, happy to the point of smug, with his great system. The only thing that ruined it for him was trying to prove it. Which was stupid in the first place. If he was so happy, what more is there to prove?
Capiche?