You can blacklist the drivers for the "wrong" sound card
I don't know if you can do this on your laptop without killing your video driver, but in many cases you can get around a "wrong soundcard" default by blacklisting the driver for it. I had that problem on a Pentium 4 in which I had dropped an Nvidia GT520 with the blob to play 1080p video in VDPAU, causing the sound to default to an Intel device that did not work. Blacklisting that driver made the installed sound card come up first. On a laptop with AMD and open AMD drivers, HDMI sound can be disabled in the video driver itself. Don't know what the Nouveau situation is on that.
Originally Posted by Awesomeness
Pull up the output of dmesg, look for your soundcard drivers. If the HDMI shows any driver other than your video driver, blacklist it in /etc/modprobe.d and reboot. Now the sound you want to use is the only soundcard and should come right up
Pulseaudio seems to be maturing nicely-and good for grabbing web audio
I reinstalled Pulseaudio in my main system today due to a new use case: Recording the output of the sound card when the hardware does not support recording the "mix" output.
On my big 8 core, Pulseaudio 4.0 shows less CPU use than Cinnamon does, sometimes less than X. We don't have Pulseaudio 5 yet, looking forward to it. I made once change to version 4: changed "autospawn" from "yes" to "no" in /etc/pulse/client.conf so I could turn it on and off. Cinnamon's volume control applet will show up when it's running, disappear when it's not as an indicator of pulseaudio's status. I then found that the old issue of audio stutter when playing 1080p AVCHD clips in Kdenlive seems to be entirely gone, and since I didn't get a boatload of pulseaudio CPU use this should be true on the 4 cores as well. If not, I can turn it off until I am done with that job.
The pavucontrol package gives a really nice GUI for controlling Pulseaudio-including the ability to record from the mics or from the output, which busts any and all attempts by webhosts like Google to control recording sound from the Web. Now no publisher of some news video I need a clip from can defeat the combination of gtk-recordmydesktop, Audacity, and pulseaudio, at least not without going to outright DRM that in my case means it's entirely blocked. If I can stream it, I can grab it. For that matter, I don't think ANY of the cross-platform DRM schemes that are denied a "protected path" on the bus could defeat the screen grab-audio output monitor combination anyway.