This certification from THX is the highest level achievable by an A/V receiver. To earn the right to carry this logo, this receiver had to pass numerous audio and video tests employed by the world's most prestigious engineers. In addition, this carries with it the new THX Ultra2 decoding algorithms, which improve on the former THX Ultra decoding. This provides you with the ultimate eight-channel (7.1) playback of any 5.1 multi-channel program - enjoy reference standard playback of both movies and music. In addition, the video switching handles all wide-bandwidth sources, such as HDTV and Progressive Scan, without any picture degradation.