You have not helped anyone, you have provided 1/2 of the basic instructions that can be found on literally thousands of websites, blog posts, etc. Most of the good ones will start with a discussion of bass nodes and listener placement, before getting into speaker placement. That move them out from the wall, then make a triangle is not "audiophile" grade help, it is Crutchfield level (though if I remember they had a good guide at one point). There are so many half - decent to good articles on the web that writing a few things in a forum post that are not even complete, on an audiophile website is not "helping"
Real sounds don’t come from two places at the same time, then come from one place. When you recreate them coming from two places, those locations you perceive sounds to be are artificial and hence subject to things like where you are sitting, are did you turn your head, etc. Again, the center channel locks the vocals to the screen, where the majority of dialog in a movie happens. It also focuses the sound in the center, where again, the majority of action actually occurs in movies. Real sounds come from one spot in space, which a center channel defines for the center of the screen (approximately) and that make it immune to listener position, head rotation, etc. You cannot replicate that with two speakers .... and we are not even getting into the rear channels which again, two fronts cannot recreate.
