An excellent in-wall subwoofer at an excellent price the OSD-IWS8 is an 8-Inch passive sub with power handling up to 150-Watts. Few components add more to the home theater experience like a subwoofer. A subwoofer is designed to reproduce the lowest of audible frequencies and will give you that spine-tingling rumble effect that takes you out of reality and into the plot. OSD Audio in-wall subs are passive devices meaning they do not include a built-in amplifier so you will have to provide additional power to drive the sub. The beauty of in-wall subs is that they can give you that thunderous room-filling bass without actually filling up floor space. Note: Requires Additional Subwoofer Amplifier.