Just did some testing.
10 channels, 0 extras, No Upmix/downmix. Seems to work perfectly.
This appears to present a 7.1 channel. I swap channels (my DAC is 5.1 configuration) and all channels play as expected.
From same zone I can now play, 4.0, 5.0,5.1 and my 10 channel decoded atmos. Fantastic!!!
With 5.1 channel and 4 extra configuration, I think there is still small issue, and it's kind of difficult to see.
Matt, I'll send you an e-mail regarding this.
At first I thought this configuration was ok, because when I play a 5.1 file it looks ok but I believe something is amiss.
I created a series of 10 channel test files. Only one channel in each file has audio data. With 5.1/4 configuration, channels 5 & 6 play silence and channels 6 & 7 each show 2 channels of audio being output by JRiver (instead of the 1).
These same files play correctly with the straight 10 channel configuration.
Word of caution..... I'm not the greatest Audacity user, but I think these files are adequate for testing
I also tried the 7.1 and 2 extra configuration. I need to look at this some more, but on first glance it seemed that instead of being mapped to 7.1, the container is mapped to 5.1 channel layout. Need to do some more testing on this one.
There also seemed to be issue with DSP dialog saving its configuration after changing the channel layout. On several occassions when switching between 7.1/2 and 5.1/4, the channel mapping never seemed to switch and it was just completely wrong. I may have switched the output format before playback had stopped for the current track, but not positive.
At this point, the only thing that fixed the channel mapping was closing down JRiver and restarting.