What makes an interconnect sound like it does?

What makes speakers sound different?

With interconnects, it sounds like you have the idea. What are they made of? Geometery, insulation, termination, the connector's themselves, cryogenically treated, and the quantity/quality of everything that was used to make them all change the sound. There is no universal secret formula to making "good" sounding interconnects- it typically involves a lot of trial an error, a great understanding of science and math and the ability to replicate your creations the exact same way time and time again.

Just some thoughts, the looser the cable is wounded together, the less mechanical vibration will "pollute" the singal path.

Low mass terminations will help in that department as well as reducing emi/rfi.

And, slightly less resistance/higher gauge on the ground wire does provide for a smoother more spacious sound.

Conductors, as long as they are atleast 99.95% pure is good. As for silver, soft annealed seem to be it thing for the moment. Palladium is similar and doesn't corrode but costs a lot.

"What makes speakers sound different?"

Glad you asked. Not because I think this is an appropriate place to discuss this question (that's for another thread), but becuase your question facilitates a good analogy.

I can make some generalizations about the sound of a speaker that is based upon an electro-static design vs. a speaker based upon dynamic electro-mechanical design. A sealed "acousic suspension" design vs. a ported "bass reflex" design. 1st-order crossovers vs. 4th-order corssovers. Etc...

Now, are these generalizations accurate all of the time? Nope - that's why they are called "generalizations." However, it does give you things to consider. I think it would be interesting to discuss generalizations about cable design.

Everything. Quantity, type, and size of conductors; conductor materials; how the conductors are braided, twisted, etc.; insulation material; outer jacket; connector type, material, and design; method of termination and materials used; type and amount of heat shrink. There are many others. Fine tuning often takes years of experimentation.