I'm trying to get 5.1 surround sound to work using:

HDA ATI SB, ALC887-VD Digital
IEC958 (S/PDIF) Digital Audio Output

and it almost works. Using alsa's speaker-test utility I get front and center channels but both surround speaker channels play through the front speakers rather than the surround speakers. No LFE. ( I ran speaker-test -diec958:CARD=SB,DEV=0 -c6)

Using mythtv's speaker test I get I similar results but, interestingly, the LFE works as well from mythtv.

I suspect that, for whatever reason, Ubuntu is not seeing/configuring the device correctly because in the Settings, Sound tab I only have a choice for IEC958 Digital Stereo -- no surround sound options are present, and the "Test Speakers" function from in there only shows the two stereo speakers, of course. The sound device is a RealTek ALC887-VD on an ASUS M5A78L-M mobo.

Any ideas of things to try? I've poked around online for many hours now to no avail.


I finally cracked the nut by adding the following to /etc/asound.conf (had to create the file), then restarted ALSA with alsa reload:

pcm.a52 {
  @args [CARD]
  @args.CARD {
    type string
  type rate
  slave {
    pcm {
      type a52
      bitrate 448
      channels 6
      card $CARD
  rate 48000 #required somehow, otherwise nothing happens in PulseAudio

Then finally aplay -L lists a52, and in PulseAudio I can now choose new digital surround profiles on the configuration tab.

While I love Linux, this is not something for your grandpa to figure out...

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