Crystal Acoustics Award Winning THX&reg; Select Certified 12" Subwoofer for Powerful and Dynamic Sound -Black Gloss/Black Ash Awarded THX Select Certified Subwoofer with built-in amplifier 12'' woofer and two ports for a room-filling bass 200W built-in amplifier for realistic listening levels without compression Flat frequency response for tight and controlled bass Auto On/Off function for easy operation