Gonna cause more heresy by suggesting the Bassculture replacement again

it definitely gets rid of the nasal mids. I think the stock pickup suits alot of sounds, but for the ones it doesn't the Bassculture manages it, only thing it won't help the ATK do is fat oldschool sounds. My ATKs gonna get alot fatter sounding near christmas when I get my Seymour Jazz Hotstack grafted in though
Also you could try going passive, I've done both, and I prefer the sound without the preamp involved, makes it sound a little less modern, again just something that suits my style a bit better.