on my H/K you can enable Dolby Virtual Speaker, which as Dolby claims simulates 5.1 with just two speakers.
However, there is also a Dolby VS Wide mode that can be used on top of an existing 5ch. configuration. Needless to say, I was very impressed. The volume was louder, clearer and the surrounds were noticeably more enveloping. MUCH better than plain Dolby Digital 5.1 for movies and just as good if not better than DTS.
Don't know if the 5ch. VS wide mode is available on receivers other than H/K though.
tried to google the 5ch. VS wide mode (still using 5.1 speakers) but got no results.
Has anyone tried this?