True, but how far out can I be?How well can a 2ch setup represent the engineers intent if your 2 speakers aren't set up exactly as his.
I know my 2-channel system is non-optimum in my room because the necessary listening position and speaker position to minimise exciting and hearing room modes means the speakers subtend slightly less than 60 degrees to my ears, but with my 5 channel system the "sides" are in the back corners of the room and I found no way with my Marantz multi channel pre to just have rears rather than sides and still use Audissey to get timing and FR "correct".
Anyway I do have some surround music recordings but the bulk of my records and CDs collected over the last 60 years are stereo (or mono...) so 5-channel is probably used once or twice a month with videos.