Stuart, when I used the term "surround" in reply to Octavian, I was referring specifically to using Logic 7 or DPLII to place the ambience contained in a stereo recording on the sides or in back where it belongs. In the concert hall the great majority of the sound reaching the listeners doesn't arrive as direct sound from the front but rather as ambience reflected from the side and back walls and ceiling. Although no home reproduction can be totally realistic, having these sounds which should come from the side or back instead coming only from front speakers doesn't help in creating the illusion. Alan briefly touched on this in past issues of the newsletter, including his "Stereo's Intrinsic Flaw: Why Multiple Channels Are Better" and also his discussion of DPLII. You might check these if you haven't read them in the past.
I wonder if you were thinking primarily of something like all channel stereo which has the unnatural effect of sending the same material to the sides and/or back as was reproduced from the front and would be best(relatively speaking)if all speakers were identical. When the ambience is properly steered to the surrounds by the better processors, such as DPLIIx or Logic 7, the effects that you mentioned don't occur and the common 80Hz crossover works well. The degree to which this increases the realism varies from recording to recording depending on how much ambience is present in the stereo channels, but is almost always a significant benefit.
