I have my sub 15 gain set at half 12 0clock.
That setting has the sub 82db at the main seat 10 feet from front of woofer.
I usually listen at -20 db sometimes -10.
Never once have I dialed the trim in my processor down or up. All settings are set to flat.
If the bass was lacking it’s either poor sub placement or crappy source material. Not a fan of eq-ing anything.