Comment 57 for bug 494099

On 08/13/2012 09:19 AM, Christopher M. Penalver wrote:
> Michael F., could you please file a new report by executing the following in a terminal:
> ubuntu-bug linux

This may be inadvisable. I have some additional information, though not
enough (yet) to exactly pinpoint the root cause.

First off, this problem exists on all distributions that I have tried
that use PulseAudio as the audio system of choice, regardless of sound
card (as long as you're not a standard 2-speaker stereo setup). More
strangely, I noticed on my Gentoo install (I've no way to verify this on
ubuntu at the moment, as it won't work on my computer due to graphics
driver issues of some sort) that certain sounds, such as the
notifications from GNOME, play through all six channels correctly, while
media players (e.g., Rhythmbox, Banshee) exhibit the problem as
frequently as every track change.

From what I can tell so far, that means that the problem is narrowed
down to (at least) media players, PulseAudio, or a difference in
configuration between GNOME's audio notifications system and media
players themselves. I can't say for sure, because I haven't had the
chance to go digging in the sources for the various projects yet to try
to figure out what's going on.

If I had to hazard a guess, though, since the one thing I've noted in
common among all systems which have this problem is the presence of
PulseAudio, that should probably be tentatively listed as the origin of
the bug.

 --- Mike

--
A man who reasons deliberately, manages it better after studying Logic
than he could before, if he is sincere about it and has common sense.
                                   --- Carveth Read, “Logic”