To understand car stereo speakers, it helps to think of sounds as falling into three basic categories: high-frequency sounds, low-frequency sounds, and mid-range ones. Most people think of low-frequency sounds as bass and high-frequency ones as treble. The woofers and subwoofers of a car stereo’s speaker system handle the bass sounds, while tweeters handle treble.
Groundshaking bass, that’s what subwoofers are all about. It’s not just the volume that creates the thumping vibration so familiar to anyone who lives near a teenager or a hard-core car audio fan, it’s the types of sounds subwoofers are designed to handle. Subwoofers pick up the very low-frequency sounds (100 Hz or less) that ordinary bass speakers can’t handle.
The basic purpose of the amplifier in a car audio system is to amplify the sound coming from the pre-amplifier before feeding it to the speakers. Since most installed car audio system amplifiers have relatively low power, it is common practice among car audio enthusiasts to install an aftermarket amplifier. Although many people think the main reason for getting a higher power amplifier is simply to make the car’s audio system louder (and it will do that), an amplifier also improves sound quality at all volume levels.