The general model that I think wiring makers tend to follow is the notion that each of the 3 physical elements of cable design (connectors, conductors and insulation) of any given wire necessarily contibute, in their own unique ways, to sonic degradation. You could think of it, for simplicity's sake, the way an oscilliscope would see the wave form - that is, some electrons in the signal path are arriving on time and others are arriving late...each wiring element contributes in its own way to the total degradation effect of each and every wire design, every design being somewhat unique. But, in general the later the arrival of more and more electrons causes more smearing...which translates into less sonic cohesiveness and more of the sonic sensation that the music is being electronically reproduced...a more "canned" sound, if you will. The thing is, with wiring of different designs from different makers (or possibly even differing designs from the same maker) these differing effects in fact accumulate. That is, if for example both the IC's and the speaker wires have the same (or very similar) detrimental effect on the sound, then their paired impacts will be singular. But, if the IC's have a different negative impact on the sound than, say, the speaker wires (seen as a different delay pattern in the oscilliscope), then BOTH sets of degradations will be heard combined. The more sets of wiring in a system that have differing delay patterns we have, the more complex the overall delay pattern we will be hearing. That's why same-maker wiring is often recommended. Actually, none of this is exactly new, I think it was first noticed many decades ago, but, if anything, the idea has sort of fallen through the cracks over the years, I suppose in the ever-quickening rush to the latest and greatest in cable designs out there, but it's still perfectly valid. Nothing wrong per se with mix-n-match either, even if the advantages ought to at least outweigh the disadvantages, but it's perhaps most helpful to begin with in system building just to be aware that this effect does actually exist.