DESC: The YST-SW015 is a compact subwoofer with surprising power, excellent bass dispersion characteristics, and the fine sound quality you expect from Yamaha. It incorporates two of the same technologies as Yamaha's top-line subwoofers: Advanced YST and QD-Bass. It also offers a Bass Action Selection System, phase control, and other useful functions. Ideal for both home cinema and audio systems, as a main or second subwoofer, the YST-SW015 provides excellent value . . . and excellent bass! .