Bose Acoustimass 10 Series IV Home Entertainment Speaker System (Black) 5.1-channel home theater speaker system for large rooms Includes Acoustimass bass module, four Direct/Reflecting Cube speakers, and a center channel speaker Powered Acoustimass module adds drama to music and movies Direct/Reflecting cube speaker arrays blend reflected and direct sound to produce stereo sound almost anywhere Horizontal center-channel speaker array visually complements flat-panel TV screens