Axiom Home Page Forums General Discussion Stereo Crossover setting for a Sub

I recently purchased a REL sub Q150E to go with my 2 channel Rotel/Axiom system (see below my system). I use High-pass level connection in my sub, but I don't seem to set the crossover in the sub right. I initially thought it sounded right around 40 MHZ but then I moved it up to around 60 and sounded kind of better. What do you guys do with your Axiom floorstanders. Any suggestions??