The Bowers & Wilkins ISW-3 is an in-wall or in-ceiling subwoofer designed to offer the maximum level of bass with the minimum amount of impact on the room. This is the first integrated subwoofer by Bowers & Wilkins to include mechanically balanced drive units. This reduces vibration increasing performance & allowing installers more flexibility with where they can install this subwoofer. The twin drivers vent through a waveguide allowing the visible grilles on the side of the unit to be as small as possible making this the most discreet subwoofer that Bowers & Wilkins have released. This unit can be mounted in two ways allowing it to be fitted in either the wall or ceiling increasing the usability & versatility of this subwoofer. The separately purchased SA250 Mk 2 amplifier is suitable for powering this subwoofer with its 250W of power.