crossover help

grb3963
grb3963 Posts: 43
edited May 2011 in Speakers
I have a sony str-dh510 reciever

polkaudio monitor 50 series ll (front) ? Set at 80Hz
sony sa-w2500 (sub)
sony ss-cn5000 (center) 85Hz-50,000hz Set at 170hz
sony f6000 (rears) 40Hz-50,000Hz Set at 80Hz

was told to double lowest frequency range for each speaker to set crossover point, but i dont know if this is true. can someone please help.

thanks