The door speaker amplifier output is a single channel that is wired in parallel to the factory tweeter and woofer to deliver a net 2ohm impedance load to the factory amp to deliver 40 watts. With the aftermarket crossover you can place it in the kick panel there and grab the wires and run separate wires to the tweeter and crossover, or you can find a spot in the door and choose which ever lead is easier to grab (normally the tweeter since it runs on the door vs in it. Tape off the other lead so you don't short it out. done.