How to Bridge Two 8-Ohm Subwoofers

There are many different ways to wire different combinations of car amplifiers and subwoofers. One common combination is that of two 8-ohm subwoofers connected to a bridged two-channel amplifier. This setup provides sends a strong power output from the amplifier to two subs, ensuring plenty of bass for your system. It's not only effective, but it is easy to wire as well.

Things You'll Need

• Speaker wire
• Wire cutters/strippers
• Screwdriver

Instructions

1. Cut a length of speaker wire long enough to reach from your amplifier's speaker terminals to the speaker terminals of your first 8-ohm subwoofer. Pull apart the positive and negative leads of the wire at each end so that there's about one inch of separation between them. Insert the ends of the leads in your wire stripper and remove 1/2 inch of insulation from both leads on both ends of the wire.

2. Loosen the speaker terminals of the amplifier with a screwdriver. Loosen the terminals for "bridged output"--this will either be marked on the amp or in the amp's manual. Slide the positive and negative leads of the speaker wire into the terminals--the positive lead into the positive terminal and the negative into the negative. Tighten the terminals with a screwdriver to hold the wires in place.

3. Cut a length of speaker wire long enough to reach from the terminals of your first 8-ohm subwoofer to the terminals of your second subwoofer. Pull apart the positive and negative leads of the wire at each end so that there's about one inch of separation between them. Insert the ends of the leads in your wire stripper and remove 1/2 inch of insulation from both leads on both ends of the wire.

4. Twist together the bare wire on the leads on the end of the first wire with the leads on one end of the second wire. Twist positive to positive and negative to negative.

5. Push in on the first sub's terminals to open a hole in the terminal posts. Slide the wires into the terminals and release the terminals to clamp the wires in place. Put the positive wires in the positive terminal and the negative in the negative.

6. Push in on the second sub's terminals to open a hole in the terminal posts. Slide the remaining speaker wire leads into the terminals and release the terminals to clamp the wires in place. Put the positive wires in the positive terminal and the negative in the negative.

Tips & Warnings

• Turn off the power to your amplifier or stereo system when wiring the subs to the amp.

References

• "Car Stereo Cookbook"; Mark Rumerich; 2005
• "Car Stereo Speaker Projects, Illustrated"; Daniel L. Ferguson; 2000