Well I have some really bad noise which I am assuming is from a ground loop. It is a sort of loud pop when turning the subs on, and also the subs keep playing when the volume is at zero(like a "hum" almost...) I put in a ground loop isolator today that I got from Radio Shack and it eliminated all of the noise but the bass is VERY low(my door speakers overpower the subs...) Even if I crank the gain all the way up, there is still barely any bass. Plugging the normal RCAs back in makes it go right to how it should be. The way I have it right now is, normal KNU RCAs to an RCA coupler, then into the GLI, then to the amp. Would the coupler affect it or is it something to do with the GLI?