The Videostage 5 Decoding Circuitry of the Bose 3-2-1 GS Series III DVD home entertainment system lets you relish five-channel surround sound. The TrueSpace Digital Processing Circuitry of this Bose DVD home entertainment system delivers multi-channel sound output for outstanding audio performance. The Acoustimass Module of this Bose home entertainment offers low-frequency reproduction to the lowest frequencies, even if the music is played at the loudest level. The High-Definition Multimedia Interface of the Bose 3-2-1 GS Series III DVD home entertainment system contains superior video data via an individual cable for refined quality picture. The Bose Link of this Bose DVD home entertainment system lets you connect other Bose speakers and systems, adding to its flexibility.