The problem was casued by changing over from the Axioms, the 850s are a bit taller than the 80s, and I built the cabinet to fit the 80s. I'm happy with having the front, center, and rears all matched, so changing the center to something else was not an option in my thinking.
But having everything in a roll-out is just not practical in my case, so time to resolve the issue.

ROCK 'N' HAXIOM Theater