Bosso:

Yes, I do indeed set my center speaker's crossover to 150 Hz to spread the dialog somewhat across the front of the soundstage. The center speaker doesn't need this though, as it has two 12" woofers.

I got the idea for doing this from when I was working on the restoration of the original "Superman" movie. When they originally mixed the movie in England in 1978, they low-passed the dialog from the center to the left and right front speakers, giving a kind of 'wide stage' feel to the dialog that I liked. They don't do this anymore, in fact dialog is very rarely panned from the center speaker. They used to pan the dialog to match the position of the actor on the screen, but it was a bitch to work with, and ended up sounding un-natural in some circumstances. So now the dialog is just sent to the center speaker.