Sony SA-WM20 Active Subwoofer

Features: Advanced SAW Design: Combining a specialized speaker for deep bass with a built-in amplifier to provide power, this component features Sony's patented subwoofer design. In addition, this Super Acoustically Loaded product provides bass all the way down to the lowest musical frequencies (28 Hz) from a compact cabinet. Woofer: The SA-WM20 has a 8" long-throw woofer for deep, accurate bass. Amplifier: The 8" long-throw woofer is powered by a 50-watt amplifier. Surround: For a smoother response and improved durability, the woofer uses a rubber surround. Bass Port: There is a front-firing bass port for improved bass response. Controls Front Panel: * Power Button: turns the subwoofer amplifier on or off * Level Control: rotary subwoofer level control * Cut Off Frequency: variable low-pass crossover adjustable from 50-200Hz * Phase Switch: allows you to select normal or reverse for best bass * Power Indicator: illuminates in green when the subwoofer is receiving power Inputs and Outputs Back Panel: * Line In: one RCA pre-amp level input  * Speaker-Level Input/Speaker-Level Output: spring clips for speaker-level input and output Enclosure Bass Reflex Video Shielded Yes Woofer Size (inches) 8 Woofer Composition Paper Firing Direction Front Preamp-Level Inputs Yes Speaker-Level Inputs Yes Speaker-Level Outputs Yes Low-Pass Crossover Freq 50-200Hz High-Pass Crossover Freq None Phase Switch Yes Amplifier Output (watts) 50 Frequency Response 28-200 Hz