I'm trying to setup my android box(4.4) to output 5.1 sound through my USB Sound card. It works well on Linux and Windows. but there is poor documentation on Android regarding audio devices. I tried editing /system/etc/audio_policy.conf by changing AUDIO_CHANNEL_OUT_STEREO to AUDIO_CHANNEL_OUT_SURROUND at the usb section of the file and it still works the same way. can anyone refer me to something else to do in order to enable multichannel audio?