Klipsch RSW-15 Reference Series Powered Subwoofer - Black Low level inputs also operate as an LFE input for compatibility with 5.1 digital sound formats Adjustable low-pass crossover lets you configure the subwoofer to your room's acoustics Easy-to-reach, side-mounted volume control for simple setup and convenient level adjustments Combines a 15-inch rear-firing Cerametallic active driver with a 3-inch voice coil, a 30-pound motor assembly and a 15-inch front-firing passive radiator High output BASH digital high efficiency hybrid amplifier delivers 650 watts continuous, 2400 watts dynamic power