Wire is usually one of the most contentious subjects for audiophiles. This thread alone is proof enough.
I thought I would kick in a bit. I have been a critical listener for most of my life as a career. I started as a navy submarine sonarman. I also taught the art of critical listening to other sonarmen. After I retired I worked developing acoustic algorithms for systems. To teach a computer how to do it, you first have to understand how you do it.
There are a number of issues which make this subject difficult. When teaching, I learned that everyone has a different way of getting to the answer. How they get there isn't important, just getting the right answer. We each had different things which tickled our neural net. That's why we call it an art. It is very subjective.
As audiophiles there certain things we each listen for which brings us delight. Add in the different music we listen to, different volumes, different listening conditions including equipment, room environments, background noise and is it any wonder that we find different requirements for wire? Now add in medical conditions, hearing loss, tinnitus etc and its a very complex set of parameters.
Everything between the recording and your ear is a filter. EVERYTHING.
Wires are just another type of filter. If you are driving ESDs you probably have very different requirements for warmth. I was using a warm sounding amp, into some warm sounding speakers, in a carpeted room with a number of wall hangings. I went for a silver clad high purity copper cable. It gave the system a bit more clarity especially in the top end.
I also enjoy the psycho imaging. Enhancing the sound stage is important to me. I look for equipment, including wires, which enhance that.
I think phase is the least mentioned yet most important aspect to sound. It is thee phase relationships which define the music, especially the imaging, and it also is important when considering speaker placement. If you get multiple arrival paths from the speaker to the listener, some of the frequency will be in phase and some will be out of phase. When it is in phase, it is additive and will make those frequencies louder and when it is out of phase it is subtractive and we get spectral hole punching. The skin effect in wire messes with the PHASE relationships and creates multipath within the cable itself. The electricity near the surface can slow and arrive a very minutely delayed time intervals than that which is traveling deeper. Its these time intervals which tell our brain location of the sound. We use that in everyday life without even realizing it. Poorly made, rough wire can exacerbate the loss of this information. This is the reason some companies polish their wire in an attempt to get their wire nearly perfectly smooth. Oxidation also can create similar effects so they try to eliminate as much of it as they can through high purity wire, insulation, factory sealed ends and contacts of precious metals. Precious metals because they don't oxidize and preserve the music, especially the phase. All these Extras in wire manufacture costs more.
People who say wire doesn't make a difference because you can't see it on an oscilloscope really don't understand sound. Even someone who is pretty good with a scope and has a decent scope, has a hard time catching phase differences in narrow-band tones. Music is broadband noise, ie spread spectrum. Catching the phase of broadband noise is much more difficult. It can't be done without very sophisticated equipment. In short, oscilloscopes aren't ears connected to a highly trained neural net, like yours. (Chances are if you are reading this you have a highly trained, acoustically centered neural net, congrats.)
You can't tell Jagger from Hendrix from YO-YO MA, much less see the rosin dripping from the horse hairs of his bow with an o-scope. Ok, that's an exaggeration. I never heard his rosin but you can hear the coarseness of the horse hair. You can't capture it on an oscilloscope. But the more accurate the system, the better you can hear the hair. I like to hear the hair.
In the recording studio, the musician can play with his setup to get the sound he wants. He can adjust things to make up for the variables of the room and yes, the cable he is plugged in with. Importantly, there is a different cable for every mic and instrument. In our home setups all the music is combined and pumped through those few cables. I think they should be pretty good, much better than studio grade.
My brothers are professional musicians. They don't really "get" the audiophile thing. They are really only interested in how the music is put together, the performance.
I think most musicians look at us a raving madmen.
But then we are.
Nick