I run Klipsch Quintet II speakers (bookshelf size or a little smaller) configured as right, center, left, r rear, l rear with an 8" powered sub.
I don't know what a crossover is, so I doubt if I have any?
My old system was configured differently, with coax out of the cable box to the TV and audio out of the TV to the receiver with composite connections.
I usually listened in Neo6 Cinema, but can't get there with this configuration. Most of my other sound field programmed presets seem to be working, but the sub only kicks in when I'm listening to a different source.
Hope that helped!