What a great idea! A Mini Subwoofer thats also a complete system!

The Atlantic Technology PBM2 Powered Bass Module is now shipping!
The PBM2 provides versatile, bass-rich home audio solutions for portable audio sources, computers, TVs, and distributed audio.
The PBM2 combines a powered subwoofer, a stereo amplifier for add-on speakers, and an innovative circuit that automatically switches between two sources without the need to manually change sources. it can be used to add music to any interior location without running cables back to a central hub, and integrated into a distributed audio system.