I'd probably lose this bet....

I dont think you will find "the best" cable. Let me choose the cables and the rest is easy. I have been cable tested before and picked the different cable 100% of the time. If I can get it correct 100% you pay. Areyou near the bay area? Jallen

Bababondoman, if your speakers are higher impedance, like 16 ohms, it may well be that you won't hear much difference.

But if you have four ohm speakers the cable is critical, and 20 feet will not work with any cable on four ohms- you will lose definition and impact. This is one of the disadvantages of four ohm speakers- the cables should be kept as short as possible!

As to whether you could correctly identify each cable in a blind test, I know I would not want to be shown up in such a test, but OTOH that is not to say that you won't hear consistent differences between the cables. One on one tends to work much better for hearing those differences.

If you look at the amplifer/cable/speaker interface, there are four electronic factors at play: purity of materials, gauge of the conductors, length of cable and the characteristic impedance (which is combination of inductance, capacitance, resistance, caused by the geometry of the cable). Even though 'experts' will tell you characteristic impedance has nothing to do with audio frequencies, it does seem to play a role- you can easily hear the differences between cables if they do or don't match the impedance of the speaker.

Of course, no cable is going to match any particular speaker perfectly. That is why while you will hear differences in the way of improvements in some comparisons, you will also hear tradeoffs. This is why there is a thriving cable industry :)

Let's not forget inductance of straight wire. For instance 20' (counting both ways) of gauge 14 copper speaker wire has inductance of 12.64uH equal to reactance of 1.6ohm at 20kHz.

I once suggested a bet that I would identify 20 out of 20 different interconnects,if listened to them in my system,and allowed to take notes-as I do not trust my short term memory any more-for how long has that been the case?
There was one character in particular who doubted my ability.When I realized that this wager meant having uncouth people in my apartment,I said -what the hell and dispensed with the circus.

Kijanki, yes, a long cable like that can thus be seen by the speaker as a higher output impedance of the amplifier resulting in a lowered damping factor. As you point out, this likely has more effect at high frequencies, but if we are talking about hearing differences between cable, its not rocket science (although there is math :)...) to see that there could be an audible, measurable and repeatable difference.