[pulseaudio-discuss] IEC958 on USB Sound Blaster issue
pulseaudio at ml.shredzone.de
Wed Jan 29 05:23:55 PST 2014
I think just found an issue with PulseAudio. I'd like to discuss it here
before I open a bug, because I'm not sure if it is really an issue.
My goal is to connect my notebook to a 5.1 surround amplifier via SPDIF.
For that purpose I have bought a Creative USB Sound Blaster X-Fi HD. It
was a good choice for the features I need.
The X-Fi HD works almost plug-and-play. When I connected it via USB, it
was immediately detected by PulseAudio. Even the volume knob worked out
of the box. My amplifier also detected a signal on the SPDIF line, and I
selected the IEC958 port in pavucontrol. However, I could not play
anything. The sound was just muted regardless of all the pavucontrol
settings I tried.
I searched the web and found other people having the same issue, and
also one solution. It seems that the SPDIF output is a different
hardware device. 
In the /etc/pulse/system.pa I added this line:
load-module module-alsa-sink device=hw:0,1
After a restart, I was finally able to hear sound!
However, the SPDIF output is now shown as a separate Output Device in
pavucontrol. It also does not offer the "Advanced" options for setting
AC3 and DTS. (According to the ALSA vendor matrix, the X-Fi HD SPDIF
output supports AC3 and DTS.)
The IEC958 port of the original X-Fi HD device is still shown and still
Now I wonder... Shouldn't PulseAudio detect and map the hw:0,1 device to
the IEC958 port, so the system.pa tweak is not necessary?
If you need any command or log outputs, please let me know...
I don't have much experience with PulseAudio and ALSA, though. I'm using
Thanks for your help!
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