With the Pioneer S-21W, songs or movie soundtracks will have much more impact. This compact subwoofer has a driver that's aimed down to distribute bass tones through the room evenly. This means it doesn't matter where you are in the room, you can always hear and feel the bass. Aim the bass reflex port at your listening position and create the perfect bass sound. The buttons at the back allow you to adjust the bass level to your own preference. This allows you to easily switch between a subtle or sweeping bass.