this is a simple problem to fix... i am assuming your using kde as your desktop manager... well, kde has something called the "Controll center", well, its name is self explanitory... its controlls stuff... like centers (this is one of me bad jokes)...

there you can change many things, like sound settings, login stuff and that...

you might find what you want there...

hopefully i have been helpful (and i didnt scare you ewith the joke0