Ok, I have installed a 500 Watt X 4 Kenwood amp, and utilized the speaker level inputs from the 4 speaker outputs on the head unit. The question is, what gauge wire should this be?

Seems to me, you don't need much since it's not drawing any power. The speaker level inputs into the amp are little tiny wires, looks like 20 guage??? So I used Cat 5 cable from my head unit to the amp for the 4 speaker level inputs. Is this ok? OR, should I put in some real wire like 14 gauge? Am I loosing an signal?

PS- System sounds ok, just wondering.