Ubuntu – Change default sound device

The cause of the problem was that the Onboard Audio was set to "Auto" in the BIOS: meaning when the BIOS detected the HDMI audio controller, it disabled Onboard Audio.

Setting Onboard Audio to "On" caused the Onboard Audio controller to reappear in Ubuntu alongside the HDMI Audio.

I had the same problem. I'm not an expert but this is what worked for me.

For what I've understood the problem is that pulse is loading by default the hdmi profile of the sound card. That means that even if you set the default sink as alsa_output.pci-0000_00_1b.0.analog-stereo when pulse try to use that sink it can't find it.

The solution I've found is to manually configure pulse to make it load the desired profile when it starts. To achieve this you have to edit /etc/pulse/default.pa and at the end of the file add this three lines

set-card-profile alsa_card.pci-0000_00_1b.0 output:analog-stereo
set-default-sink alsa_output.pci-0000_00_1b.0.analog-stereo
set-default-source alsa_output.pci-0000_00_1b.0.analog-stereo.monitor

the first line set the desired card profile. In my case was output:analog-stereo, you can have a complete list of profile running :

pactl list cards

the second and third line sets the default output and input respectively.

Another thing you can do is add a configuration for alsa to use pulse. Look in your home directory for the .asoundrc file, if the file does not exists create it and write this inside:

pcm.pulse {
     type pulse
}
ctl.pulse {
     type pulse
}
pcm.!default {
     type pulse
}
ctl.!default {
     type pulse
}

then reboot.

Now you should have the audio coming from your pc speaker by default.

Hope this help.