There are hundreds of things that effect the sound and can be heard by most anyone on a good system and these things do not change the measurements of the DUT. You can give me 10 Purifi amps that all measure the same. I will mod each one sound way, way different from each other. These amps will all measure the same.....exactly the same......but they all sound different. The objectivists do not believe this.....they will argue and argue but they will never listen to equipment with mods and see if there is a difference......they say the same thing about cables off the floor, cables, footers, other tweaks, amp stands, etc. to infinity.
Just yesterday I was tweaking my system and it sounded kind of dry and recessed. I had heard Cat Stevens here sounding much better......However, I was listening with the cover off. Before, I felt the cover on the unit made it sound too fat and rolled off. However, that was really a problem with the amp module that I corrected last week.......so, I put the cover back on and the sound changed dramatically. His voice was now way bigger sounding and everything was more real.....really MOVED me.
Without listening tests (and they do not need to be blind or double blind.....unless you are deaf or double deaf....he he) you have no idea of what something will sound like. I can remember what something sounded like years later......really! I do not have golden ears......I just listen. You come to my house and I will demonstrate tons of things that alter the sound.....and none of it can be measured.....this is the truth the objectivists (who do not listen) will fight and fight. These kinds of threads never go anywhere becasue the Amir type people just keep pounding on their EE bibles....saying the same thing over and over. This game is way, way more complex than measurements. I was one of the first people on the planet to do straight wire bypass testing on 7 inch pieces of wire (back in the late 70s). None of the wires sounded as transparent and pure as the half inch reference.....not even close. We have much better wires today that would be very close. I did not even know about wire directionality back then (every wire....whether solid core or stranded..... (no matter if it is PCOCC or ordinary copper wire) sounds different when you reverse the direction of the wire. Did I say this game was infinite? Well, it is. The measurement people make like it is so simple.....it is not. Doing serious listening tests on a super system is critical to KNOWING ANYTHING about sound.