like one need two ears only to get directional cues in real life situations, you only need stereo to produce all kind of directional cues. problem is to get correct setup for recordings. for headphone listening the effect is replicated by binaural recordings. but binaural set up has its own limitations. for normal stereo recording it is very difficult to replicate the effect as it demands considerable experimentation with placement of mic. there is a chesky stereo recordings ( not binaural) which creates behind your head sound with two speakers only. it was recorded with a single stereo mic. with properly set up speakers ( correct toe in) the behind you sound is reproduced correctly. modern recordings need lot more mixing of different sounds specially in movies so the effect is generated in processing rather actually recording for obvious practical problems. if someone is not concerned about the quality of recordings , some hand held portable recorders create that much wider recording of live events. few days back I recorded my Hugo+ benchmark ahb2+ kef r300 system sound with Olympus ls100 handheld recorder in 24bit 96khz and in between my kids were knocking on the side door. when I listen to that recording it sounds as if there is really a sound coming from extreme right from out side of the headphone. so it is possible to record and reproduce such sounds with stereo setup .