Pioneer EQ-6500 9-Band Car Equalizer "set crossover low pass 10" Questions

...Low, Mid, and High. Subwoofer: Off, Normal, and Reverse. Subwoofer frequencies: 50, 63, 80, 100, and 125 Hz. (Note: I do not have a subwoofer, and I am using stock 04 Nissan Frontier speakers) High ...