Presumably, you are using the line level subwoofer output on the receiver and feeding that to a line level input on the subwoofer. If there is no "bypass" for the crossover in the subwoofer, set it to the highest possible setting. You will be using the receiver's crossover, so you want the subwoofer's crossover to interfere with this as little as possible.
You don't give the frequency response of your main speakers, but I will presume that they go at least as low as your center channel (if that is not the case, then you need to tell us about your main speakers).
You don't say, but for the purposes of my advice, I will presume the frequency response of the speakers you give are the ratings for +/- 3 dB. If that is not the case, then you need to tell us in order to get the right advice for your equipment.
Assuming that you can only set one frequency that applies to all speakers (some receivers can set the crossover different for front, center, and surround), set the receiver to 100 Hz. You can try it a little higher or lower as well, but given the fact that your center is - 3 dB at 100 Hz, if you go lower, then you will be having a dip in the frequency response from around 100 down to whatever you set the crossover point for the center channel, and that is not good. If you set it higher, you are more likely to be able to tell where the subwoofer is by the sound. This is because the higher the bass, the easier it is to localize by sound, and 100 Hz is already pushing things a bit.
Sorry about that,
My Front and Rear Speakers are 75Hz to 33kHz
My center is 100Hz to 33kHz
The sub has a control on it called a High Filter Bypass that goes from 50Hz to 150Hz
In the manual it says to set the Filter to 110Hz for proper tone balance between the speakers. What should my AVR be set at?
Here is the Specs:
MAIN/SURROUND
Driver Complement 3" high compliance woofer with rubber surround
1" ferro-fluid cooled balanced dome tweeter
Input Power 40 watts nominal, 100 watts music power
Frequency Response 75 Hz-33kHz +/-3dB
Sensitivity 87dB/2.83v/1m
Impedance 6 ohms
Dimensions W x H x D = 4-1/4" x 7-1/2" x 5-1/2"
CENTER
Type Two-way, dual bass reflex, magnetically shielded bookshelf type
Driver Complement Dual 3-1/2: high compliance woofers
1" ferro-fluid cooled balanced dome tweeter
Input Power 50 watts nominal, 125 watts music power
Frequency Response 100 Hz-33kHz +/- 3dB
Sensitivity 87dB/2.83v/1m
Impedance 6 ohms
Dimensions W x H x D = 12-1/4" x 4" x 5-1/2"
NS-P610 WOOFER TECH SPECS
Driver 8" spruce cone driver, magnetically shielded
Amplifier Built-in 70 watt Yamaha Advanced Active Servo Technology
Frequency Range 30-200Hz
High-Cut Filter 2 position
High Cut Slope 24dB/oct
Dimensions W x H x D = 9-1/4" x 14-1/3" x 12-1/2"
Weight 18.2 lbs.