RME Fireface UCX II 40-Channel USB-B Audio/MIDI Interface - Manual (Page 21)

User's Guide Fireface UCX II © RME
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Note: Since Windows Vista the audio application can no longer control the sample rate under
WDM. Therefore the driver of the Fireface UCX II includes a way to set the sample rate globally
for all WDM devices within the Settings dialog, see chapter 7.1. As the change within the system
requires some time, record/playback should not be started immediately, but only after at least 5
seconds after a change.
Tip: the current CPU load can be used to determine if the audio subsystem has finished the re-
configuration.
8.2 DVD-Playback (AC-3/DTS)
Popular DVD software players can send their audio data stream to any AC-3/DTS capable re-
ceiver via the Fireface UCX II SPDIF output.
The sample rate must be set to 48 kHz in the UCX II Settings dialog, or the software will only
playback the down-mixed analog signal via SPDIF.
In some cases an UCX II output device has to be selected in > Control Panel / Sound / Play-
back< and be set as Default for the software to recognize it.
The DVD software's audio properties now show the options 'SPDIF Out' or similar. When select-
ing it, the software will transfer the non-decoded digital multichannel data stream to the Fireface.
Note: This 'SPDIF' signal sounds like chopped noise at highest level. Try to avoid mixing and
routing the signal to your loudspeakers, as they might get damaged.
Multichannel
DVD software player can also operate as software decoder, sending a DVD's multichannel data
stream directly to the analog outputs of the Fireface UCX II. For this to work select the WDM
playback de
vice ’Loudspeaker’ of the Fireface UCX II in > Control Panel/ Sound/ Playback < as
Default .
The playback software’s audio properties now list several multichannel modes. If one of these is
selected, the software sends the decoded analog multichannel data to the Fireface UCX II. To-
talMix can then be used to play back via any desired output channels.
The typical channel assignment for surround playback is:
1
– Left 2 – Right 3 – Center 4 - LFE (Low Frequency Effects)
5 - SL (Surround Left) 6 - SR (Surround Right)
Note 1: Selecting the Fireface to be used as system playback device is against our recommen-
dation, as professional interfaces should not be disturbed by system events. Make sure to re-
assign the selection after usage or to disable any system sounds (tab Sounds, scheme 'No au-
dio').
Note 2: The DVD player will be synced backwards from the Fireface. This means when using
AutoSync and/or word clock, the playback speed and pitch follows the incoming clock signal.