The SSM2005 Circle Surround decoder produces true 5.1-channel surround soundfield from any stereo source, including VCD, DVD, VCR, CD and FM stereo broadcasts. The SSM2005 is also compatible with encoded sources, such as Dolby ProLogic and Circle Surround encoded movies and music. External delays and noise reduction processors are not required for the surround channels. Circle Surround encoded stereo signals will produce a full 360 soundfield when played through the SSM2005. Recording engineers can encode sounds to any of the five speakers surrounding the listener. Left Front, Right Front, Center, and differentiated Left and Right surround channels are generated, providing a realistic ambiance effect with either 4- or 5-speaker configurations.