Configuring MPD with an 5.1 external surround sound card - raspbian

Question

I've read tons of threads about this, but i cant figure it out.
So i have a MPD server running on Raspbian, with an external sound card attached to it. Music works fine trough mpd with the 2 channels, but not for 6 channels.
Also i am confused what is the task of all programs involved.
So there's alsa. I Have tried to change the /etc/asound.conf to many different configurations. Like:
pcm.!default {
type route
slave.pcm surround51
slave.channels 6
ttable.0.0 1
ttable.1.1 1
ttable.0.2 1
ttable.1.3 1
ttable.0.5 0.5
ttable.1.5 0.5
}
But it did not work. My current settings are:
pcm.!default {
type hw
card 2
device 0
}
ctl.!default {
type hw
card 2 #If you want to set HDMI as output ,turn 0 to 1.
}
Then there is pulse audio. I am not sure if the function of both programs overlap, or if you should use them together. To the pulseaudio config file /etc/pulse/daemon.conf i have edited the following line:
default-sample-channels = 6
Furthermore i have added the following line to /etc/pulse/default.pa
set-card-profile 2 output:analog-surround-51
load-module module-native-protocol-tcp auth-ip-acl=127.0.0.1 # IP of l$
But i am not sure it has any effect at all.
So last there is mpd configuration which I had configure at ~/.mpd/mpd.conf
audio_output {
type "alsa"
name "My ALSA Device"
mixer_type "software"
mixer_control "PCM"
}
If i change alsa to pulse i cant hear sound. Furthermore, the command speaker-test -c 6 -t wav
IS working for 6 channels. Since mpd is configured with alsa, and speaker-test does work, i guess that it is pulseaudio that creates the surround sound. But how can i configure MPD to work with surround sound?
Does anyone have any idea? Any help is much appreciated!
Here is the ouput of aplay -l
xcb_connection_has_error() returned true
card 0: sunxicodec [sunxi-CODEC], device 0: M1 PCM [sunxi PCM]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: sunxisndhdmi [sunxi-sndhdmi], device 0: SUNXI-HDMIAUDIO sndhdmi-0 []
Subdevices: 1/1
Subdevice #0: subdevice #0
card 2: Device [USB Sound Device], device 0: USB Audio [USB Audio]
Subdevices: 1/1
Subdevice #0: subdevice #0
and
Update:
If i play sound as the mpd user it also works with surround sound
sudo -u mpd speaker-test -c 6 -t wav

Answer 1

Eventually this worked for me:
pcm.ch51 {
slave sl2
#slave.channels 6
type route
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_slave.sl2 {
channels 6
pcm "hw:1,0"
}
In ~/.asoundrc. The table thing duplicates sound to other speakers so all 5+1 speakers are used. The pcm "hw:1,0" selects my external usb sound card.
Additionally in ~/.mpd/mpd.conf
audio_output {
type "alsa"
name "My ALSA Device"
channels "6"
device "ch51"
You select the device specified in asound.rc