Hi Jmack! The subwoofer is responsible for low frequency sounds, like the rumbles of an explosion in an action movie or the bass guitar and drum in your favorite music. It adds rich bass tones and deepens the sound quality you hear, but since the subwoofer only plays low tones, it will be silent when low frequency sounds are not in use. If you'd like louder (or softer) bass from your subwoofer, you can adjust the level by toggling the WOOFER button on the soundbar remote, and then adjusting the level from -6 to +6. To set the subwoofer volume level to 0, press the button down. ^Patty