Kimber Kable

Why don't you hook them up to your speakers and find out for yourself?  I do know the 4pr are not 10 gauge.

What stereo5 said, +1.     Kimber’s 4PR is 13 AWG.     If you could shorten and double the run, you’d have about 7’ of 10 AWG, per channel(same AWG as 8PR).     Alternatively, if you’re able to shorten the run; you could try bi-wiring.     Shorter’s always better, regarding speaker cable, anyway.     Of course: compare them as is, to what you’re using now, first.     There’s more to building decent cables, than simply the wire’s gauge.