Not sure you're understanding. The sub preouts on the headunit are completely independent from the speaker wires. You would disconnect the High input plug from your amp (you dont even have to disconnect the high input harness from the speaker wires if you don't want to). And plug rca's into the subwoofer preouts on the radio, to the rca inputs on the amp. That is how the amp gets it's signal, from the rca's. The way it is now, it is getting it's signal from the speaker wires.