Default installation of Crunchbang 11 Waldorf.
The shortcut for controlling volume is recognized by X properly, which is confirmed by the visual feedback. However, the actual sound is not affected.
xfce4-volumed is not controlling correct sound card in fact.
lspci | grep -i audio will list all the audio devices on the box. Apparently,
there are two audio devices on my box; one of them is for HDMI.
Then, we need to tell
xfce4-volumed explicitly which one to use. There’s no
GUI for this, and we could achieve this using the following command:
xfconf-query -v -c xfce4-mixer -l