Dynamic (fluctuating) volume when there are 2 or more active sound sources.
Description: When playing a game and listening to music at the same time, the volume for either of the applications will fluctuate, for example the music volume will lower down when there is a high noise coming from the game (like explosions).
I haven't found any fix for this except the workaround that's presented below.
Windows XP workaround fix
Set Windows Volume to 80%-90%. I noticed that this issue is only present when Windows volume(or panel volume) is above 80-90%. So my recommendation is to not exceed this limit.
Windows Vista/7/8/10 workaround fix
Workaround here is slightly different from the one in WinXP, you'll have to set the volume in each application at 80% or below. You can set Windows Volume to 100%.
Please note that moving the mixer playback sliders in ASUS Audio Center above "76" or moving digital volume sliders in C-Media Control Panel above "0" dB will cause the same issues.
Until further notice, all driver versions (UNi or Asus) have this problem.