Just to clarify what I mean by system specific, let me lay out a scenario based on cables we used to sell during my retail days (forgive the references to older products):

Customer 1 (Steve) walks into the store and buys a pair of Apogee speakers and a Conrad Johnson tube amp. Being that both products tended to be on the warm / dark side of the frequency spectrum, a cable that counterbalanced those qualities, such as products made by Straight Wire, would be just the ticket. I'd recommend a pair of Music Ribbon speaker cables and one of their interconnects.

Customer 2 (Dave) walks in and buys a pair of Martin Logan CLS and a Motif amplifier. Now, both of those products are very revealing and extended in the highs, so the Sraight Wire products would make the amp / speaker combo sound way too bright and strident. To counterbalance this combo's tendency to be too bright and fatiguing, I would recommend a pair of MIT 330 interconnects and MIT Music Hose speaker cables.

Why? Compared to the Straight Wire products, the MIT products are more warm, liquid and rolled off on top. I would correct the problems with the amp speaker combo by using cables that worked well for the tonal qualities unique to that specific system.

Dave calls Steve and says he has GOT to try the great new MIT cables he bought. So he brings them over, hooks them up to Steve's system and... they sound like crap compared to the Straight Wires. Steve thinks Dave got ripped off and has hearing problems. In actuality, both guys have good cables for their systems, but they don't perform well in each other's, as their speakers and electronics have such different sonic signatures.