How to Install a High & Low Impedanceby Allen Coleman
When you are hooking up equipment like a powered amplifier to a car audio system and your deck doesn't have the proper connections for an amplifier, you will need to use a high/low impedance converter. Audio signals are sent from a head unit by a high-level signal or a low-level signal. A high-level signal is an amplified signal like the one sent to your speakers, a low-level signal is a nonamplified signal sent out of the red and white phono outputs.
Locate the two green wires and the two purple wires coming from the back of your deck. They are the wires for the right rear and left rear speakers. One of the green wires and one of the purple wires will have a black line on it; these wires are the negative wires. The other wires without the lines are the positive wires.
Remove about an inch of the jacket on all four of the wires using your wire cutters. Make the cuts about 6 inches down from the back of the deck. Be careful not to cut through the wire underneath the colored jacket.
Take the two wires marked "Right" on the hi/lo impedance converter. One of the wires will be labeled positive (+) and one will be the negative (-). Attach the silver wire on the positive wire to the wire exposed on the purple wire and the silver wire on the negative wire to the exposed wire on the purple wire with the black line. Attach the wires by wrapping the silver wires around the exposed wires. Keep the wires together using electrical tape.
Take the two wire marked "Left" on the hi/lo impedance converter. One of the wires will be labeled positive (+) and one will be the negative (-). Attach the wires by following the same procedure as in Step 3.
Insert the plugs on the RCA cable into the output on the converter. Make sure to match the colors of the plug with the colored output. Plug the other end of the RCA cable to your amplifier's input.