How to Match Subwoofers With Amps

Subwoofers powered by amplifiers are an essential element in a high-powered, high-performance car audio system. There are many brands and sizes of subwoofers on the market, and just as many amplifiers of differing configurations and power settings. Matching the right subwoofer to the right amplifier is essential if you want the best performance and the best bang for your buck.

Difficulty: Moderately Easy

Instructions

1. Find out the specifications of the car subwoofer you're interested in. The key specification you'll be looking for is RMS power. Simply put, RMS power is a rating of the ability of the subwoofer to handle a continuous power signal. Ignore specifications for peak power -- these are typically overrated, and don't provide a realistic measure of the subwoofer's capabilities.

2. Find a car amplifier that has sufficient outputs for your subwoofer(s). For example, if you're going to power one subwoofer, a mono (single channel) amplifier or a 2-channel amplifier that can be bridged to a single channel is perfect. For two subwoofers, a 2-channel amplifier or a 4-channel that can be bridged to 2 channels is appropriate.

3. Ensure that the power output of the amplifier is a good match for the sub(s). As in Step 1, examine the RMS power output of the amplifier, not peak power. Match the power output within 15% -- for example, if the subwoofer handles 100 watts RMS, choose an amplifier that puts out 85 to 115 watts RMS power. It's better to err on the side of a little extra power, rather than not enough.

4. Look for options that will make your amplifier work better with a subwoofer. These include subsonic filters, which eliminate distorting ultra-low tones, and variable low-pass filters, that let you fine-tune the signal coming in from your car stereo. If you like extra "thump" in your tunes, look for a bass boost feature as well.