The Logitech Z-680 is a gigantic 5.1 sound system designed for a pure digital 5.1 Surround Sound with THX. The system features built-in Dolby Digital and DTS hardware decoding. Dolby Pro Logic II creates realistic 5.1. Surround Sound from stereo music, movies and games. Optical and coaxial outputs allow simple connection to nearly any audio appliance. The Z-680 includes an innovative Digital SoundTouch Control Center for easy operation.