I recently took the plunge on a new surround system, consisting of an AVR equipped with all sorts of DSP ambiance generator programmes and usual extractor programmes (Dolby Pro Logic IIx, DTS Neo 6, etc.). My question is which one should I use depending on the source so that the pairing is correct? For example last night I was watching a rock concert Bly Ray which was encoded in three different formats - DTS-HD Master Audio, Dolby Digital 5.1, LPCM Stereo. I changed back and forth between them and they all sounded great to my ears, but which one would be the most appropriate from a point of view of how the gig was recorded and meant to be heard? In other words, which of these should I use for best audio and what programme should I pair it to?