Ubuntu – Inverted surround channels

hdmipulseaudioservicesspeakers

I'm encountering an issue with surround sound on Ubuntu 11.04.
I managed to play sound trough HDMI but the channels are inverted.
For example when Pulse Audio plays on the center speaker, it goes through my LFE. Same thing on the speaker test included in the sound preferences channel.

While searching topics about this issue I tried editing /etc/pulse/daemon.conf by changing the channel-map setting – to no avail. Maybe I didnt use it correctly ?

Any idea to swap those channels and have my 5.1 working correctly?

System specs :
Ubuntu 11.04
AsRock aion330
HDMI amp

Thanks in advance!

aplay -L gives this result:

default
    Playback/recording through the PulseAudio sound server
pulse
    Playback/recording through the PulseAudio sound server
front:CARD=NVidia,DEV=0
    HDA NVidia, VT1708S Analog
    Front speakers
surround40:CARD=NVidia,DEV=0
    HDA NVidia, VT1708S Analog
    4.0 Surround output to Front and Rear speakers
surround41:CARD=NVidia,DEV=0
    HDA NVidia, VT1708S Analog
    4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=NVidia,DEV=0
    HDA NVidia, VT1708S Analog
    5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=NVidia,DEV=0
    HDA NVidia, VT1708S Analog
    5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=NVidia,DEV=0
    HDA NVidia, VT1708S Analog
    7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
iec958:CARD=NVidia,DEV=0
    HDA NVidia, VT1708S Digital
    IEC958 (S/PDIF) Digital Audio Output
hdmi:CARD=NVidia,DEV=0
    HDA NVidia, HDMI 0
    HDMI Audio Output
dmix:CARD=NVidia,DEV=0
    HDA NVidia, VT1708S Analog
    Direct sample mixing device
dmix:CARD=NVidia,DEV=1
    HDA NVidia, VT1708S Digital
    Direct sample mixing device
dmix:CARD=NVidia,DEV=3
    HDA NVidia, HDMI 0
    Direct sample mixing device
dsnoop:CARD=NVidia,DEV=0
    HDA NVidia, VT1708S Analog
    Direct sample snooping device
dsnoop:CARD=NVidia,DEV=1
    HDA NVidia, VT1708S Digital
    Direct sample snooping device
dsnoop:CARD=NVidia,DEV=3
    HDA NVidia, HDMI 0
    Direct sample snooping device
hw:CARD=NVidia,DEV=0
    HDA NVidia, VT1708S Analog
    Direct hardware device without any conversions
hw:CARD=NVidia,DEV=1
    HDA NVidia, VT1708S Digital
    Direct hardware device without any conversions
hw:CARD=NVidia,DEV=3
    HDA NVidia, HDMI 0
    Direct hardware device without any conversions
plughw:CARD=NVidia,DEV=0
    HDA NVidia, VT1708S Analog
    Hardware device with all software conversions
plughw:CARD=NVidia,DEV=1
    HDA NVidia, VT1708S Digital
    Hardware device with all software conversions
plughw:CARD=NVidia,DEV=3
    HDA NVidia, HDMI 0
    Hardware device with all software conversions

gnome-volume-control is indeed set to Digital Surround 5.1 HDMI Output. The speaker test is affected by the channels issue, though.

Best Answer

To set up the correct mapping in HDMI 5.1 sound when the channels are configured incorrectly you should try the following in the command line

  1. pulseaudio -k
  2. gksu gedit /usr/share/pulseaudio/alsa-mixer/profile-sets/extra-hdmi.conf
  3. Find the HDMI-surround section there in that file. Switch the incorrect speakers in channel-mapping and save the file.
  4. Run speaker-test -c6 -twav
  5. If it is still incorrect, go back to step 1.

Tested on Ubuntu 12.04 with an NVIDIA ION (zotac motherboard).

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