For the original amp configuation:
Head Unit Settings:
Sub control at 2/3
LPF at 80Hz rolling off at 24DB/o
Bass Boost On (12db at 50Hz)
I set the output voltage using a DMM to 28.3 (sqrt(400x2)) with the head unit at the max volume I turn it to (about 2/3rds up - no audible distortion) using a 50Hz test disc at 0db. I've noticed that my sub plays a few magical notes, not surprisingly around 50Hz, and very low and very high notes not nearly as loud. Would turning bass boost off and resetting the gain give me a better response across all frequencies?