@loekf - absolutely it matters, Use WASAPI for passthrough, not DirectSound. DirectSound uses system mixers which essentially prevent passthrough. Make sure your Windows settings are set for WASAPI exclusive mode as well.
System: XBMC HTPC with HDMI WASAPI & AudioEngine - Denon AVR-3808CI - Denon DVD-5900 Universal Player - Denon DCM-27 CD-Changer
- Sony BDP-S580 Blu-Ray - X-Box 360 - Android tablet wireless remote - 7.1 Streem/Axiom/Velodyne Surround System If I have been able to help feel free to add to my reputation +/- below - thanks!