I'm with Tru on this one... CloneDVD does NOT touch the audio tracks in any way. There is no compression or molestation of the audio at all...a straight duplication. It's easy enough to tell what's on the copy, though...just load it into CloneDVD and let it tell you what kind of audio tracks it finds. For the record, there is indeed AC3/2 on some movies...that is NOT pro logic and will show up as Dolby Digital on your receiver. Just a thought.