Adding commands to shutdown and reboot

[utu]

Greetings jvfc678,

As one suggestion, read up on /etc/rc.local. Then ..
you can probably add aumix setting just before exit 0 to the /etc/rc.local
you already have.

First, cp /etc/rc.local /etc/rc.local.orig , in case you need it sometime later,
then use sudo laumeafpad /etc/rc.local to do the editing,
and save the edited /etc/rc.local, of course.

You may probably also edit .aumixrc directly.
See man aumix.