I'm using powerdvd to play the DVD, when i thought to select Motu 7.1 in audio outout, the option doesn't be there, i've just stereo pairs.
How to setup the cuemix or motu console to create an 7.1 or 5.1 channels output ?
Thanks you for your help.
Edit :
I found a example of that in RME Fireface(extract of the manual), it's exactly this option i'm looking for

Multi-Client and Multi-Channel using WDM
The WDM Streaming devices of our driver can operate as usual stereo devices, or as 8-channel
devices. The option Interleaved in the Settings dialog determines the current mode.
Interleaved not active: The WDM devices operate as usual stereo devices. The multi-client operation
works as described above with WDM, ASIO, MME and GSIF.
Interleaved active: The WDM devices can also be used as 8-channel devices. Unfortunately the
Kernel Mixer, active with any WDM playback, then always occupies and blocks 8 channels at
once, even when WaveLab or the Media Player perform just a stereo playback (2 channels).
So:
If any stereo pair within an 8-channel group is used, the whole 8-channel group is blocked.
As a result, no second stereo pair of this group can be used, neither with ASIO, MME nor
GSIF.
The Fireface provides three 8-channel groups: the analog inputs 1 to 8 and the two ADAT ports.
Starting MME, ASIO or GSIF playback on any of the stereo pairs of an 8-channel group prior to
starting a WDM playback will prevent the Kernel Mixer from opening the 8-channel device, as
two of its channels are already in use. The Kernel Mixer then automatically reverts to open a
stereo device for a stereo playback