ALSA usually loads it's settings from these locations:
/home/%USER%/.asoundrc - this loads special custom stuff like which mixer is used by default, daemons, and other things
/etc/modules.conf - this usually handles the oss emulation portion and also multicard assignments for output and identification of those cards as well as options if needed.
/etc/alsa.conf or /etc/modprobe.d/sound.conf (depending on OS distribution settings) - this is where mixer settings are loaded from for alsactl.
If needed, check your card at ALSA's main page on extra information for your sound card: