Do your ears deceive you?

Nonsense. This isn’t a scientific forum. No one here owes you any "rigorous" explanation or any other kind of proof, although of course you’re free to conduct your own experiments and share the results. If the empirical evidence described by users here is insufficient for you, perhaps you are in the wrong place.

@cleeds

I think you misread me. I don’t require any explanation. Evidence described by user’s perceptions are perfectly adequate for me, with no further claims or explanations beyond that. If they like it, they like it. Period. But, if the manufacturer starts making technical claims, it is scorn worthy if they don’t back it up. If they’re not going to back it up, why make a technical claim in the first place? If it’s just how users perceive it, who cares how it works? Why bother with all the technical hocus pocus, or credentials of the person who designed it? If it works, it works!

I’m not curious enough about it to do any formal testing myself. I’ve listened, and since my listening skills aren’t good enough to be impressed, I’ll leave it to those who can perceive what the fuss is all about and are curious about how it actually works to do those kinds of experiments. This is my selfish side. I’m interested in things I can hear, things that matter to me. I hear a lot of problems with 2 speaker stereo. Even though it sounds quite good, it’s a hack job way of creating stereo sound. I’ve got much bigger fish to fry than cable improvements. The problem is, I have no reasonable idea how to fry them.

The cables question is ill-formed.

I would agree that there is a difference between the worst and the best. There are many physical properties to consider: Resistance; Capacitance; Inductance; Dielectric Absorption; RF rejection; connection integrity..

So yes, there are differences based on physical principles, and understood to physics. Are they important? Yes - but system dependent. If you seek transparency, then that's easy - decent connectors and quality cabling like Canare will set you up nicely, and be somewhat better than lamp cord.

But, for example, if you have an over-bright system, then a high resistance, high capacitance, high inductance, high DA cable may correct it to the point of listenability. Of course, you might do lots better with better components, but cables do make a difference. They are just the worst way to do it. IMO.

@steakster I can't believe you are calling out some of the biggest shysters in the industry as credible.  I'm surprised you didn't include Ted Denney.

As for the rest, I do NOT, under ANY circumstances, believe that any of these companies do anything more with Quantum-whatever than misquote, bend and stretch truth, and use to deceive gullible audiophiles with meaningless word salad and pseudo-scientific nonsense.  Some of the claims of these companies are so preposterous that it is astounding that ANYONE would believe them.

        The site has yet another runway builder.

         May as well try teaching a box of rocks,

                       To sort your socks!

      Many cable manufacturers are using the results, regarding the following mentioned science, as guidance in building cables for audio systems.

        The only experimentation left for one to do, is try them in their own system/home and determine if they make a difference in their own listening experience.

                                            Another rerun:

       That the studies of QM and QED have been revolutionizing virtually every branch of Science, since the early 1900s, has been firmly established.

                                          That's called, "HISTORY"!

https://www.livescience.com/33816-quantum-mechanics-explanation.html

https://www.sciencedaily.com/terms/quantum_mechanics.htm#:~:text=Quantum%20mechanics%20is%20a%20fundamental,quantum%20chemistry%2C%20and%20particle%20physics.

        Not to mention the multitude of modern inventions, that are the results of the same.

https://en.wikipedia.org/wiki/Applications_of_quantum_mechanics#:~:text=Examples%20include%20the%20laser%2C%20the,systems%2C%20 computer%20and%20telecommunication%20devices.

        The evidence is all around us and ONLY the most obtuse, or: willfully ignorant, could possibly ignore it.

                            To deny the above exemplifies the Dunning-Kruger Effect*!

         Were one needing a thesis submission, to a Psychology Undergraduate Office; the local Naysayer Church would make an excellent case study of the above*.