After you purchase and install a new car audio amp, you need to connect either an existing set or a newly installed set of door-mounted speakers to the amp’s right and left front outputs. The more popular car amps drive four speakers: two front-door units and two backseat units generally mounted on the back deck under the rear window. With the front-door speakers’ wiring already pulled through the door and frame, all that remains is for you to connect the two positive and two negative leads to the amp. Tips Warnings Writer Bio

How to Wire Door Speakers to an Amp - 98