Google 5 sekundi :
SOLUTION:
CONTROL PANEL > HARDWARE AND SOUND > SOUND, click Speakers, then the Properties button, click the Enhancements tab (by default, Immediate mode is selected.... I left it checked, default position). Scroll down to the bottom of the list and check DTS Connect. Apply.
You can even use the Room Correction enhancement to further produce a more desired volume from your speakers based on your configuration!
Fixed the issue. I can now restart my computer, play multiple sources, etc, without having to change anything in the sound options ever again!