Yea i think sooo, can u guide me, i'll do it my self, my pre has two ports/RCA at backside dont know exact name, Sub is embossed near to that port, the guy putted two jacks in it one with white color and the other with red color. im using 4 channel amp aswell, also my HPF and LPF fucntion is not working, means no effect whn i change, Now guide me in this regard,