In reply to:
DPLII isn't really "faked," because on lots of 2-channel recordings, the ambient information is there. It's picked up by the mikes and contained as out of phase info in the 2-channel recording. DPLII extracts the out-of-phase ambient info and redirects it to the side surrounds in an approximation of where the reflections may have originated. DPLII also adds digital delays which would also have been present in the original reflections from the sides, rear and ceiling.
I should have been a bit more specific in how i defined 'faked'.
DPL2 can sound 'faked' for some material.
I know this based on my subwoofer tests. I had turned off my main speakers so i could more easily hear the subwoofers, but in order to know what song was playing at what section, i left my surround speakers on.
The listening tests used various modes including DPL2. Several of the songs i was using to test the subwoofers had surround information reproduced in a very odd way, something i had not previously noticed as the main speakers presented such a louder impact when plugged in. Some songs (not all) caused the surround speakers to cut in and out like someone was playing with the fade knob and volumes would sometimes vary left and right.
This was a very unnatural presentation of the sounds that should be coming from music as the sound fills the room around you as other recordings played the constant 'background' type sounds you would normally expect to hear. It was as if the DPL2 approximations were not extracting constant information from the disc for surround playback or its approximations were not very good based on the source (perhaps a misinterpretation of the out of phase ambient info?).
I will have to try and remember what recordings specifically that the DPL2 mode had created this odd effect but this was awhile ago now.
