Maven

Make HDMI card be second while SB card be first one:


options snd-hda-intel index=1,0


Enable dmix with surround 5.1 support (no upmixing):


pcm.dmixer {
type dmix
ipc_key 1024
ipc_key_add_uid false # let multiple users share
ipc_perm 0666 # IPC permissions (octal, default 0600)
slave {
pcm "hw:0,0"
channels 6
# buffer_size 16384
}
}

pcm.!default {
type plug
slave.pcm dmixer
slave.channels 6
}


to /etc/asound.conf. Enable 6 channels in alsamixer, too.