I tested the Motu M4 Four-Channel Audio Interface.
Very nice device but only two playback channels can be used in roon!
Going to the “Device Setup -> Show Advanced” I only can select “Channel Layout” of 2.0. There is no 4.0 available!
In the “Signal Path” during playback I see:
- Convolution Filter: 4 path, 66k taps
- Bit Depth Conversion: 64Bit Float to 32Bit
- Channel Mapping: 4.0 to 2.0
I guess this is an issue for all Four-Channel DACs. With other Applications channel 3 and 4 can be used with ASIO and ALSA.
PLEASE ADD 4.0 to the “Channel Layout” so channels 3 and 4 can be used within Roon.