Anonymous

pcm.snd_card {
     type hw
     card 0 # change to your cards number or name
}

# 6 channel dmix:
pcm.dmix6 {
     type dmix
        ipc_key 1024
        ipc_key_add_uid false # let multiple users share
        ipc_perm 0660 # IPC permissions (octal, default 0600)
        slave {
                pcm snd_card # see below
                rate 44100
                channels 6
                period_time 0
                period_size 1024 # try 2048 against skipping
                buffer_time 0
                buffer_size 5120 # in case of problems reduce this
                                 # in case of skipping, try increasing
        }
	bindings {
		0	0
		1	1
		2	4
		3	5
		4	2
		5	3
	}


     }

# upmixing: 
pcm.ch51dup {
        type route
        slave.pcm dmix6
        slave.channels 6
        ttable.0.0 1
        ttable.1.1 1
        ttable.0.2 1
        ttable.1.3 1
        ttable.0.4 0.5
        ttable.1.4 0.5
        ttable.0.5 0.5
        ttable.1.5 0.5
   }

pcm.duplex {
     type asym
     playback.pcm "ch51dup" # upmix first
#     playback.pcm "dmix6"  # just pass to 6 channel dmix
#     capture.pcm "dsnoop:0" # doesn't work for me
     capture.pcm "snd_card"
}

# change default device:
pcm.!default {
     type plug
     slave.pcm "duplex"
}