I'd like you to perform two experiments, if you are willing. 1. Download the effects discovery sample http://code.msdn.microsoft.com/windowsapps/Audio-effects-discovery-5fd65c15 , build it, and run it. What effects does the audio driver in question provide for non-RAW background-capable media? 2. Go to the Sound control panel, double-click the default device, and disable all enhancements (there's a checkbox on one of the tabs; depending on the audio driver it could be on the "Enhancements" tab, the "Advanced" tab, or on a tab with some other name.) What does that do to the sound of your player, and to the sound of other players, and to the advertised effects for non-RAW background-capable media?