I attended a concert Sunday night here in Nashville at the Ryman Auditorium. I've been to many shows there, and the sound is almost always stellar. Sunday night wasn't quite up to par, though. Part of the reason (I believe) is that the overall level was unnecessarily loud. But I started digging around and I found this. While it focuses on the Ryman, it's a pretty informative article on the challenges faced by any live sound crew.

M22ti mains, EP175 sub, VP150 center, QS4 surrounds