I set my front 3 to large and 40hz. I've tried small and various crossovers. Large and 40 just sounds more natural to me. My theory is that at a higher crossover less of the center channels woofer is used making the dialogue sound less natural. However set the xover lower and all the woofers to be used more and it sounds more natural.
None of this makes mathematical sense because supposedly natural speaking voice of males doesn't even go below 130hz. Whether it is just in my head I can't get past the fact that once I set them to small and 80 the dialogue is a bit too bright for my liking. And it feels more grounded at 40hz. I feel letting the klipsch go full range sounds more natural.
Main room (3D blu ray, PS4) - LG 65EG9600: Denon x4000, Klipsch RC-62II, RF-62II x2, RS-41II x2, SVS PC-12NSD + Klipsch RW12d
Couple small LCDs - PS2, PS1, Dreamcast, N64, 3DO, Saturn and other various retro game collections MINT COMPLETE games