How to Wire Two Subwoofers in Series to an Amplifier

How you wire subwoofers depends on several factors, including the type of amplifier you're using, the impedance of the subwoofers and the number of subwoofers in your setup. One of the most common schemes is to wire two in series to an amplifier. This configuration is used when you have two subwoofers with a low impedance rating (2 ohms or less) and you want to increase the impedance of the overall load so the subs can be safely connected to an amplifier that will not accommodate the lower impedance of the subs.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• Tape measure
• Amplifier
• Two subwoofers
• Screwdriver
• Hex wrenches
• Speaker wire
• Wire cutters/strippers

1. Measure the distances between your amplifier and the subs, and the distance between the subwoofers. You'll use these measurements when cutting lengths of wire for connections. Take into account how you'll need to route the wires when measuring the distances.

2. Cut a single length of speaker wire long enough to reach from the amplifier to the first subwoofer. Connect this wire between the "+" terminal of the amplifier and the "+" terminal of the subwoofer.

3. Cut a single length of speaker wire long enough to reach from the first subwoofer to the second subwoofer. Connect the "-" terminal of the first subwoofer to the "+" terminal of the second subwoofer.

4. Cut a single length of speaker wire long enough to reach from the second subwoofer to the amplifier. Connect the "-" terminal of the second subwoofer to the "-" terminal of the amplifier.

Tips & Warnings

• Notes on connections: Amplifiers and subwoofers use different types of connections for speaker wire. As a rule, amplifiers use a "set-screw" type of connection--you loosen a screw or hex bolt, slip the wire underneath in the space that is created, and then tighten down. Subwoofers typically have terminals that either unscrew or are spring loaded. Unscrew the terminal and slip the wire in with the first, and push down the terminal and slip the bare end of the wire in with the second.

References

• Two subs in series wiring diagram
• List of subwoofer wiring diagrams