The key to your questions is in this line. Yes, the physical difference is minute - measurements confirm it. However in the appropriate system the perceived difference can be enormous - it is related to the mechanisms of rebuilding an illusion that should be enjoyable in the technical limitations of stereo sound reproduction. We are now dealing with psycho-acoustics, not just with engineering.
It is curious that the engineers were very efficient finding and even exaggerating the drawbacks and limitations of stereo when they were promoting multi-channel, but they quickly forgot about it ...
OK. If that's what you wish, I'll leave. I'm really not a troll.
First I read the post by microstrip. He was decent and polite and I went away to answer him. When I came back I saw there IS some tempest on the horizon. DaveC, you're overplaying it. Saying your products cost more than they should is not accusing. "In on it" is your construct. What I said was; it is impossible to sell something and say there's no need, use or advantage to it. So it is impossible for you to tell the people; "there's no need for my products". See what I'm getting at.
This is my answer to microstrip that I wrote earlier and I'm off after this.
OK, I think I understand what you're saying. Since I clearly stated "where I come from" as they say, disagreement was to be expected, so here's my next comment:
FOA I'd like to remind everyone that I don't think there is a difference at all and where I come from, proper measurements would confirm no difference. I was adopting your position to try and work with it.
You are introducing vague categories in your comment, like for example, appropriate system. Again, much like with the time needed to break-in cables, WHAT is the appropriate system, in the end, gets to be decided by you. This can't be acceptable. In the DB tests I was mentioning, invitees knew what system was about to be used. They agreed upon it.
Furthermore, I read the entire thread, advice weren't directed to "those with appropriate systems". Advice were directed to all. No one even asked about the system.
Then there's this "perceived difference". Another vague category. The adjective perceived is often used to mean "not really there". And all this "not really there" is exactly what's bothering me. For example "perceived value" is, much like the beauty, in the eye of you know who. It is not actual value you can ascribe to a certain feature or level of performance, but it's people thinking it should cost more, so you get to charge it more. Maybe you wanted to say it's small but it means a lot, but, then again, why doesn't it mean a lot in properly conducted DB tests.
Then you say "mechanisms of rebuilding an illusion". How to be polite about this... I'll say that cables have no illusion rebuilding mechanism. I have to stop here. I was sincere when I said I don't want to provoke anyone. Then, all of a sudden, you introduce stereo. But why? If there's break-in, surround should also profit from it.
Now, psychoacoustics don't cover for cable break-in. Unless you're considering marketing placebo to be a part of psychoacoustics. This is a somewhat new term in the audio community and it is expected to be tossed around a lot in the beginning. But I know about psychoacoustics. They are not at all that psycho. For example, psychoacoustics came to realize that the fact that you can communicate with someone in a loud night club is because your brain will ignore what is not of any value. Putting a signal through a cable for 200 hours doesn't affect this.
You tell me to trust my ears. I don't hear it. Then you say it is my system being inappropriate, but I assure you, it's not. Then it's "mechanics behind the illusion" and all those unknown psychoacoustics... These, and many more, are the reasons your team sounds unconvincing to my team.