One more thing.
Here is a AC3 clip, for comparison.
http://forum.videohelp.com/images/gu...lem_orig48.ac3
Please test it with
* Aud-X virtual surrond (VS) algorithm
* FFDshow HRTF algorithm (to see what I mean by linear distortions)
* AC3filter (to see the difference between the VS algorithm and a regular stereo downmix)