View source for Setting default ALSA output to HDMI audio

To view all available ALSA devices run the command ''aplay -l''. You sould see something like that:

 $ aplay -l
 **** Liste der Hardware-Geräte (PLAYBACK) ****
 Karte 0: SB [HDA ATI SB], Gerät 0: ALC888 Analog [ALC888 Analog]
   Sub-Geräte: 1/1
   Sub-Gerät #0: subdevice #0
 Karte 0: SB [HDA ATI SB], Gerät 1: ALC888 Digital [ALC888 Digital]
   Sub-Geräte: 1/1
   Sub-Gerät #0: subdevice #0
 Karte 1: HDMI [HDA ATI HDMI], Gerät 3: ATI HDMI [ATI HDMI]
   Sub-Geräte: 0/1
   Sub-Gerät #0: subdevice #0

In this case the HDMI audio output is ''device 3'' on ''card 1''. To set this as the default ALSA output, create the file ''/etc/asound.conf'' with the following content:

 pcm.!default {
     type plug
     slave.pcm {
         type hw
         card 1    # HDMI card number
         device 3  # HDMI device number
     }
 }

Just restart yor PC. That's it!