Subwoofers that you want to use with the sound system in your vehicle need to be powered using an amplifier. However, the amplifier will need to be the proper size for the subwoofer. If you already have a subwoofer, you can use information on the speaker to calculate the size of the amplifier. An amplifier will need to be big enough to power one or more subwoofers.
Look on the back of the subwoofer box or subwoofer and locate the information sticker. This provides the Nominal Impedance and the Continuous Power Handling specification of the speaker. Make a note of the specifications on a piece of paper.
Multiply the Continuous Power Handling specification, such as 100 watts, by 1.5 if you listen to dance or light music. If you listen to harder rock, then multiply the specification by 2.5. Make a note of these numbers on the paper.
Compare the Continuous Power Handling you calculated in the previous step to the power output rating of the amplifier. The power rating of the amplifier should be between 70 percent and 125 percent of the continuous power rating of the subwoofer.
