Someone will certainly correct me, but creating a sweet spot for multiple people is very difficult in a Home Theater configuration. Note that when you go to a movie theatre there are many many speakers and the place is designed for as many people as possible to enjoy.
I've come to the realization that unless you set up some sort of "stadium" style couch arrangment (i.e. couches are lined up with each other, the back one slightly higher than the other) you can't really accomplish this. Whoever is sitting directly in front of the screen between the speakers in the optimal sweet spot will get the best sound, and that's it.
Harman Kardon AVR-120,Axiom VP100,Axiom M22Ti,
Axiom QS8, Axiom EP-175