i think it takes a reboot before phonon knows about the changes in asound.conf ...

am glad that it also works for you
what i don't get is why phonon doesn't use dmix on it's one...

Phonon does not deliberately not use DMix. It is probably a configuration issue with its backend which is either GStreamer or Xine.

ALSA, without any configuration (/etc/asound.conf or ~/.asoundrc), should set up dmix automatically if your card doesn't support hardware mixing, since version 1.0.9rc2. If not, it sounds like an ALSA bug, and you should probably file a bugreport with your distro.

That said, 99% of the times I've helped someone who can't have multiple apps playing sound at the same time, it has either been a bogus alsa configuration (their distro gave them one (sometimes to get PulseAudio to work correctly, it seems), they got one from some poor misled soul trying to help them, from old ALSA configuration, etc.), or they had PulseAudio installed.

sandsmark wrote:That said, 99% of the times I've helped someone who can't have multiple apps playing sound at the same time, it has either been a bogus alsa configuration (their distro gave them one (sometimes to get PulseAudio to work correctly, it seems), they got one from some poor misled soul trying to help them, from old ALSA configuration, etc.), or they had PulseAudio installed.

Interesting but, only by curiosity, why only happens with Phonon and don't happens if several ALSA or GStreamer applications was running at the same time?

If ALSA and GStreamer can solve this problem I think that Phonon must do the same.

Ignacio Serantes wrote:Interesting but, only by curiosity, why only happens with Phonon and don't happens if several ALSA or GStreamer applications was running at the same time?

If ALSA and GStreamer can solve this problem I think that Phonon must do the same.

It has to do with the way Phonon selects the audio output to use, AFAIK (I haven't really looked into the cases where this fails). Phonon integrates quite closely with ALSA, and therefore assumes a more or less sane configuration of ALSA.