What is the best way to choose the sub's crossover setting in receiver? Should I follow the manual's recommendation? I have 5 bookshelf speakers(6.5" woofers) all set to small, and my center(3-3.5" woofers) set to small. The manual says to set crossover at 80hz. Does that sound right? My receiver has sub crossover settings of 80,100,120,and 150 hz. I also read on one of the HT forums if speakers are set to small, to set crossover at 150hz. What do you guys think? Thanks.