Although car amplifiers come with RCA input jacks, your stock stero may not support the option to send audio through RCA outs. You can still connect the amplifier with a "Line Level" connection. You connect one of the audio wires already connected to your stereo into the amplifier's "Line Level" input jack. All you need is enough wire to make the connection from your trunk's speaker to your amplifier.
Instructions
1. Connect the positive and negative ends of the speaker wire to your pre-existing trunk speaker terminals. The black, or lined, cable will be the negative; the red will be the positive.
2. Measure out enough speaker wire to reach your amplifier, then cut the wire with the wire cutters. Give yourself enough slack so the connection will be secure, without the possibility of becoming unplugged.
3. Connect the other two ends of the speaker wire to the positive (+) and negative (-) "Line Level Input" terminals on your amplifier. Make sure the "+" and "-" wires are connected to the same polarity as the speakers.
Tags: Line Level, speaker wire, your amplifier, ends speaker, ends speaker wire