Setting the Default Sound Device
If your system keeps on using the wrong device (HDMI instead of PCH or vica versa, or some other problem), then do the following so you can identify the devices number & then instruct your system to use that number/device:
- Run alsamixer - if you have it installed, just enter:
at the terminal prompt.
- In alsamixer hit the F6 function key, then you'll see the devices listed in a little box, with their numbers in front of them.
- Enter the following into a terminal:
- Choose the number of the sound device that you want to use.
- Then using your text editor of choice, put the following into /etc/asound.conf (You will most likely have to create /etc/asound.conf ).
defaults.pcm.card 1 defaults.ctl.card 1
Change the number from 1 to 0 , 2 or whatever?
- Save the file & play a movie or listen to a tune.
I can imagine that if you had need to change between two sound devices from time to time, you could write a simple script that quickly swapped from one /etc/asound.conf file to another. All it would have to do is change/swap the file extensions from asound.conf.bak to asound.conf & visa versa when desired. ;)
The core information in this page came from the ALSA Project: 
Following is a link to this page's forum counterpart where you can post any related feedback: