Ok sub is used nd I know it works had it hooked up before and it pounded. RCAs are ran from the front speakers out of the RCA on the deck and the in on the amp. It only hits when I have my music blasting to the point where I cnt hear. Nd even then it's not very loud. I'm thinking about splicing my RCA back in to where it was when I had my factory head unit. Anyone else ever have this problem? I have a Bose stock system btw with a kicker l7, boss 3600w amp, 2farad cap, and an xovision in-dash DVD