Dolby Pro Logic Iix

Dolby Pro Logic IIx is an extension of Dolby Pro Logic II technology. This sophisticated algorithm processes native stereo- and 5.1-channel material to produce 6.1 or 7.1 output channels. Dolby Pro Logic IIx expands choice in playback system configuration (allowing 5.1 , 6.1, or 7.1 playback channels) and, when incorporated into an audio/video (AV) receiver or processor it allows a convenient upgrade path from a traditional 5.1-channel sound system to 7.1 output channels. [Source: Dolby Technologies]