Onkyo is just like Marantz when it comes to being unclear about the specifics of bass management. How do you engage the bass management system on the Onkyo 494 receiver and what are the crossover points and slopes? I read an article that stated the sub output on the 484 had variable crossover points, depending on whether you set the mains to LARGE or SMALL. I see no such option on the 494. Can anybody help me?