Subwoofers are speakers dedicated solely to reproducing low frequencies. No matter what kind of music you like, or how softly or loudly you like to listen, a quality sub can really improve your overall listening experience. Car speakers are small, so they have trouble producing enough low-frequency sound to give your music realism and depth. A subwoofer can make the difference between a good-sounding and a great-sounding system. You should start by looking at component subs. A component sub is just the speaker itself — it'll need to be mounted in a subwoofer box to operate properly. In addition, you'll need to power the sub with an external amplifier. Component subs usually range in size from 8" to 15". There are models designed to operate on low or high power, and in a variety of different types of boxes. They are several different impedance and voice coil setups, so you can pick and choose among models to match up to your system design. The pressure treated double stitched ribbed foam surround along with the dual poly cotton spider helps keep the piston motion of the subwoofer linear and distortion free. Vented aluminum former holds a 3" voice coil while allowing the heat to be exchanged. (Less heat means less distortion) Specialized Hifonics dual poly cotton spider with double centering allows the woofer to handle more power with minimum distortions. Hifonics heavy duty aluminum die-cast basket allows back venting, which exchanges heat with cool air, resulting in more power handling and increased reliability. Vented high energy motor assembly with dual 70oz magnets increases power handling and increases SPL.