The down-firing design of this Klipsch Subwoofer provides more "room-filling" bass. The high output subwoofer driver effectively couples, or grips, room air, dispersing the low frequency energy consistently throughout the room. This augments the haptic sensation and "feeling, " ensuring powerful bass performance. Santoprene rubber surround with fiber-composite cone delivers extended bass response and maximum reliability. Multiple hookup options accommodate any system configuration. It is easy to connect with LFE line level or speaker wire from any receiver or component separates. Phase and low pass filters are variable to optimize performance. LED light indicates power amplifier status.