Pioneer MCACC has three filters for the subwoofer that adjust the frequency, Q or bandwidth and attenuation: this is the same as a PEQ. MCACC does not do anything under 63 Hz for the sub. I have a PEQ with my Pioneer SC 35 and there is not much EQ'ing that needs to be done under 63 Hz. The two things that can be done under 63 Hz is a bass boost around 20-25 Hz which most sub have built in and to cut a peak in the 30-50 Hz range. Cutting the peak can be detrimental to SQ and MCACC will control the 2nd and 3rd harmonic of the peak which we can hear more easily. Check the Pioneer forums and see how many people are complaining about how there subwoofer sound. I have ran 3 sub off my avr and calibrating them as one subwoofer works very well.
Klipsch RF 7 based HT 7.4, Pioneer SC 35, Acurus 200 Five, Dayton 18 Ultimxa Dual Sub Cab(2), Dayton 18 Ultimax Large Vented Sub Cab (2), on Berhinger I Nuke DPS amps, Samsung BDP F 7500, Asus/My Book Live HPC 4 TB
Yaquin VK 2100 amp, McIntosh XR 5 speakers, Samsung BDP F 7500