I am not surprised it hasn't happened again. You need to take breath step back and relax. It all comes down to your state of mind. Your are so caught up in the pursuit that it just won't happen again. I think you are trying to hard. I don't worry about it all that much and every once in a while I get treated to one of those nights.
Funny how you picked on the physics bit but passed on the fact we have had similar experiences.
Rob
Perhaps a few people here misunderstand me. I've experienced the "good stuff" over and over again: even when I started my "quest" I could do that. I learnt, by a process of trial and error, that if the system was in a certain stable state, and if I then then did a series of things, essentially resetting influences which were disturbing the sound quality, then I could get my the premium sound quality back. The problem, as I've mentioned here many times, is that this level of performance then started to fade away, each and every time -- that's where the real issue was for me then.
Nowadays, it's pretty stable: main hassle is that it takes several hours to come up to top notch form, unless I drive it full bore from the word go. This is the advantage of having better speakers ...
Real and imagined? That is exactly how the brain works; it does create a construct from information coming in, which bears little resemblence to what the electrical impulses are "saying". I recall an experiment where they tested the optical qualities of the human eye, and sorry, that whole piece of our body is a bit of rubbish: not fit to use in a 100 year old Brownie camera. In other words, our mind "fills in the gaps", and obviously does a remarkably good job of it. And the same goes for the ear ...
Why I particularly said that, is that I just had a "ah haa!" moment. Elsewhere on the net someone tried a very simple, very short blind test, to see if making a change affected sound quality. He started well, then kept getting things wrong; as in he thought the quality remained good even though it had dropped. Then he realised what was happening: he had picked up the clues of how the sound
should be from the good version, and was subconsciously, unintentionally altering the poorer version to match the good. This was all a game being played out in his head, his brain was compensating automatically for the sound not being as good, because it
knew what it should sound like. So, once he had tweaked to this, he changed his tactics, relaxed, stopped concentrating hard, and got every following change right.
So, this says to me, and he commented the same: where does this leave the notorious DBT? That piece of meat in your skull is smarter than the "experts" would like it to be, it "fills in the gaps" if you make it easy to do so, by rapidly changing from the better to the worse. The people who instinctively let the sound swirl around a bit, like a good red wine in a deep glass, before deciding, may be doing it the better way after all ...
Frank