alsamixer (1) - soundcard mixer for ALSA soundcard driver, with ncurses interface amixer (1) - command-line mixer for ALSA soundcard driver gnome-alsamixer (1) - ALSA sound mixer for GNOME
Here is an example by using amixer to set the volumn to 60%:
/usr/bin/amixer -c 0 sset Master,0 80% > /dev/null You might want to try adding that line to to /etc/rc.local