It should help. I don't know that you will notice the difference, but the stock wiring sucks. (Including the crappy RCA cables.) If you decide to put in a new amp or do more with the stereo, you should replace these.
I think I got rid of my sub and put in new wiring the first week I had the car. But I've been known to blow a lot of money on stereo equipment (but I've been trying not to do that with this car).
Still have the same head unit but two RF Power amps, two 10" Power subs, MB Quartz components in the front doors, MB Quartz Coax's in the rear doors, 4 gauge wire to the amps, Stinger Dream RCAs to the amps and a 1 Farad cap. . .
So, nevermind, I blew that one again, but it looks like I haven't done much with it. I'll shut up now.
But bigger, less resistance wires always help. If it made no difference, then capacitors wouldn't help either.