Can we objectively rate speaker cables?

Nasaman -- you've got a point about us:)
BUT: What's da system???

Almarg aptly notes

Besides their apparently outlandish markups, what I find to be the biggest turn-off about super-expensive cables is the design rationale which is typically offered in their "white papers" and other literature.

"White-papers" for audiophile consumption are a powerful emetic!
They are up there (but do not quite reach),
"PROPRIETARY design slip-knot, direct-coupled, parallel-serial time /phase/ solar aligned crossover" and, the piece de resistance,
"DISSATISFIED with what the market had to offer, David set about to design his own .... (speakers, amplifiers, tiddly-winks, ball-gags, etc). A friend, musician of world-renown who happened to hear/ use / ? them, instantly ordered (a bundle, 69 containers...)"
Aaaargh!

Aldavis, it does matter if you understand what actual instruments sound like. It also matters that you are able to discern some basic qualities of instruments so you can listen for accurate music reproduction.

Dave, Agreed. That is necessary for comparisons. Unfortunately in this case it's not sufficient as there are plenty of people on both sides of this issue with a good working knowledge of live instruments. The problem is that there are so many other variables in play. Well designed cables will sound better than poorly designed cables in some instances. How much depends upon a ton of other factors including both the system and the listener. Listeners even those with good "aural memories" may actually remember differently from each other and you can never discount the active placebo effect of spending big bucks. My general feeling is that if YOU hear a positve effect from the cable then go for it. For ME personally above a certain price point money is better spent somewhere else.

given some deifinition of say, "warmth", there may be a consistent relationship between two speaker cable across all stereo systems.

that is, cable A may be deemed warmer than cable B regardless of the stereo system. however the degree of difference may vary from stereo system to stereo system.

would there be agreement that some Cardas cable is warmer than some Nordost cable, independent of stereo system ?

I realize that cables react have different effects on different systems, but within the same system and in general, wouldn't most people agree that an equally pure copper cable of 22AWG would sound warmer than a silver 22AWG (of identical construction)? My argument is that this is true within almost any system. So if we define the parameters, we should be able to roughly agree on "this cable is warmer than that one," unless you're in some camp that believes cables make no difference. The idea is that with such a knowledge base, we would be able to narrow our cable choices based on our own system. I know that for mine changing the LP cables to all silver has drastically improved detail and resolution while putting the copper into the digital part has made sound less analytical. I'd like to get beyond the copper vs. silver issue and be able to compare within cable type.