The Monolith by Monoprice M IWSUB82 Dual 8" In Wall Subwoofer adds powerful bass to your in wall or in ceiling home theater system. Equipped with two high end, compact, 8" polypropylene woofers, heavy duty mounting tabs, and a paintable magnetic grille, the M IWSUB82 can be used in both new construction or seamlessly added to existing systems. The 91dB sensitivity ensures an easy pairing with just about any amplifier. The Monolith by Monoprice M IWSUB82 Dual 8" In Wall Subwoofer is designed to add thunderous bass, without taking up valuable floor space.