Yamaha YST-SW315 250 Watt Powered Subwoofer (YSTSW315) 10" cone driver 250W Amplifier 20 to 160 Hz frequency range Advanced Active Servo Technology --is an amplifier/speaker system utilizing negative impedance feedback in the amp and a Helmholtz resonator in the speaker to provide strong and accurate bass. BASS Selector Yamaha's QD-Bass Technology Magnetic Shielding Continuously variable high-cut filter sets the highest frequency the subwoofer will deliver. It can be set anywhere from 40 to 140 Hz. Volume Control Signal Sensing ON/OFF: When the subwoofer detects an audio signal, it turns its power on. Phase Normal/Reverse Switch Dual Inputs-- allow the versatile subwoofer to accept either line level or speaker level input signals. Three-way speaker terminals Black Ash finish The YST-SW315's cabinet is constructed of thick MDF to increase rigidity and reduce vibration and resonance. Driver 10" down firing spruce cone driver. Amplifier Built in 250 watt Yamaha PWM type. Advanced Active Servo Technology. Frequency Response (-10dB): 20-160Hz High-Cut Filter Continuously variable from 40-140Hz High Cut Slope 24dB/oct Standy Power Consumption 0.5W Dimensions (W x H x D) 13 3/4" X 17" X 15 1/16" Weight 42 lbs.