AGAIN. its not your settings, its not the sub, ITS YOUR ENCLOSURE ENCLOSURE ENCLOSURE ENCLOSURE. How many times do people have to say that to you. Its how your box is tuned that affects the sound. WHatever else you listed does not matter in comparison. The SA 12 wont do sh*t to solve your problems, if anything it'll make it even worse. Get a box properly tuned and designed right tailored to how you like your subs to sound.
Sound and output is 70% enclosure.
AGAIN ENCLOSURE ENCLOSURE ENCLOSURE ENCLOSURE
what you want is more midbass and less of actual 45hz and below subwoofer bass.