How to Wire a Dual 2-Ohm Speaker to a 4-Ohm Amp

Car amplifiers are designed to operate properly with a specific speaker resistance (impedance) or range of resistances, measured in ohms. Likewise, speakers or subwoofers have specific resistance measurements. Some subwoofers are built with multiple voice coils so that the wiring of the subwoofer can be adjusted to accommodate the needs of different amplifiers. The combination of a dual 2-ohm speaker (usually a subwoofer) to a 4-ohm amplifier is quite common.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• Speaker wire
• Wire cutters/strippers

1. Cut a single speaker wire lead with your wirecutters long enough to reach from your amplifier to the subwoofer's first set of speaker terminals, and strip 3/8 of an inch of insulation from each end of the wire. Take into account the path the speaker wire will need to take, and account for any turns or twists. Connect this wire from the "+" output of the amplifier to the "+" input of the subwoofer's first set of speaker terminals. Please see "Tips" for information on how to make these connections.

2. Cut a single length of speaker wire long enough to reach from the first set of speaker terminals to the second set, and strip 3/8 of an inch of insulation from each end of the wire. Connect this wire between the "-" connection of the first set of terminals and the "+" connection of the second set of terminals.

3. Cut a single speaker wire lead long enough to reach from your amplifier to the subwoofer's first set of speaker terminals, and strip 3/8 of an inch of insulation from each end of the wire. Take into account the path the speaker wire will need to take, and account for any turns or twists. Connect this wire from the "-" output of the amplifier to the "-" input of the subwoofer's second set of speaker terminals.

Tips & Warnings

• Different models of amplifiers and subwoofers will have different methods for connecting speaker wires. These are the most common ways of connecting speaker wires. For most amplifiers, loosen the Phillips or hex-head set screw until an opening large enough to slide the speaker wire in appears. Push in the speaker wire's bare end and tighten the terminal. For subwoofers, loosen the terminal's post with your fingers until a hold appears in the post. Slide the wire in and tighten the post to hold the wire. Some subwoofers have push-in terminals--push down on the post to open a hole in the terminal, slide the end of the wire in, and release the terminal to hold the wire tight.

References

• "Car Stereo Cookbook"; Mark Rumerich; 1999