The car subwoofer enhances the low-pitched frequencies, i.e. the bass. For best effect, subwoofers are fitted as low in the car as possible (under the seats, in the trunk or in the lower part of the doors). If your car radio is not equipped with a special subwoofer link, you have to apply a dedicated amplifier. The majority of the modern car audio systems can be extended to accommodate a subwoofer.