The Science of Cables

I've tried diy single-core & branded cables, and I have heard differences, consistently. Ditto with various branded cables. I'm saying different, not better, worse, etc.
I've often wondered what the real issue with cables is: do people object to *expensive* cables because they are expensive, ergo snake oil, or do people object to the idea that differently constructed wires result in different sound?
If it's the first, I've found that cables tend to be expensive when they sound good in a number of systems. The production price can be a secondary consideration.If it's a matter of rejecting the idea that different cable constructions affect the sound, it becomes a religious topic.

“I ask this question......how sophisticated must a system be to truly hear the difference in sound from a modestly priced cable and the super expensive ones? Is it just a matter of money?”

I’ll play devil’s advocate. In order to obtain a “sophisticated system,” one must not overlook cables. I often hear people say, “don’t spend money on cables, save it and put it where you’ll get better bang for your buck, like speakers.” I’m not sure I agree with this completely. Yes, get good speakers, but then go on to bring the rest of your system up to spec and that includes good cables. Even if you have the best speakers, you’ll never realize their full potential until you give the rest of your system the attention it deserves. Based on comments from others, when they have swapped a decent pair of bookshelves into their “sophisticated system,” they were blown away by just how good a mediocre pair of speakers can sound.

“I have noticed the members with the most technical knowledge here seem to have less expensive wires than the ones with less knowledge.”

I like to believe I have technical knowledge - two engineering degrees and an engineering license. A funny twist on your quote is that while I do have very inexpensive cables, I have put a significant amount of time and effort into DIY cable efforts. When I say “good” cables I don’t necessarily mean expensive - just good in the sense that they compliment your system and that one has put in the necessary amount of time and trial and error to get a lot out of their system. My latest escapade was changing some tweeter speaker cables from small gauge, solid core with a poor dielectric to the same wire with an air dielectric. Wow, the improvement it made!! Harsh treble that makes you want to turn down the music is no more. 

So while I don’t currently spend a ton on cables, I recognize their importance and go to great effort to pick the right ones. Sometimes you do have to spend a little bit - pure silver is expensive - no way around it. 😃

Like I posted earlier, and what mrdon considers funny, ears are the best instrument for evaluating sound. Just like some people can see better than others, some people can hear better than others. Simple, yes. Funny, maybe (just like vision and hearing, a persons sense of humor varies just as much). The physical shape of a persons ears affect how they hear. If that were not the case, everyone would agree that "this sounds great" or that "this sucks" and, well, that ain't how it is. Can you hear me now?

And those dark energy boys can just keep playing in the dark; I will stick with my nine foot universe.....it encompasses the things I can embrace, reject, or control. No need to call NASA

All I can say is some people get hung up on measurement and are too quick to say don't waste your money because all wire sounds the same...snake oil. I agree with those that say trust your ears...all I really care about (with-in reason) is what I hear.