Denon AVR-X6400H Owner's Manual page 142

Contents Connections
Auto surround playback
This mode detects the type of input digital signal, and automatically
selects the corresponding mode for playback.
Perform stereo playback when the input signal is PCM. When the input
signal is Dolby Digital or DTS, the music is played back according to the
respective channel number.
1
Press PURE to select "Auto".
Auto surround playback begins.
Front panel Display
Playback Settings
142
Rear panel
Tips
Remote Index
Appendix