Yamaha YST-FSW100PN Slim 6.5" Powered Subwoofer (Piano Black) (Discontinued by Manufacturer) Powerful 6.5" multi-range driver with magnetic shielding Slim design is only 6.19" deep to match flat-panel displays Advanced Yamaha Active Servo Technology for deep, powerful bass Half-pipe port for minimizing extraneous noise 130 Watts of dynamic power