you really dont need two rca coming off the deck for sub out. the two rca setup is typically left and right output. If they deck your using only has one rca for the subwoofer (amp) then all you'd need to do is connect it to either of the rca's on the amp. You could also get a Y-splitter rca to turn the single into 2 rca's for the amp, this way should gain some sound/db
im no audio expert so i could be completly wrong :crazy:
im no audio expert so i could be completly wrong :crazy: