On my system, multichannel playback from 4 and 5 channel sources don't work with MC15.
Here's how my hardware is configured:
Channel 1: Front left
Channel 2: Front right
Channel 3: Front center
Channel 4: LFE / subwoofer
Channel 5: Surround left
Channel 6: Surround right
Channel 7: Rear surround left
Channel 8: Rear surround right
When I play stereo or 5.1 surround material the channel assignments are always correct. For 4 channel (quad recordings), I should be getting sound from channels 1, 2, 5 and 6. However, the channel assignments are going to channels 1, 2, 3 and 4. For 5 channel recordings, which you can find for some classical recordings and these are typically the same as 5.1 recordings without the LFE/sub channel, I should be getting sound from channels 1, 2, 3, 5, and 6, but instead sound is sent to 1, 2, 3, 4, and 5.
EDIT: Actually, channel mapping priority for 4.0 (Quad) would be:
1
2
5
6
and, channel mapping priority for 5.0 would be:
1
2
3
5
6
But I'm not sure how to handle this. This isn't a problem with other players like foobar2000. Foobar plays 4 and 5 channel sources correctly.
I couldn't figure out how to attach 4 and 5 channel samples, but would be happy to do so, or I can send the clips to someone via email or ftp. Whatever works best.