That's strange.....
I have nailbombs in a swamp ash body and the tone is big and fat no matter where its at.....N-bomb's got more bottom end than Kim Kardashian.....you can see where this is going.
My only suggestion is to check how far the pickups are from the strings...try moving them closer would be my best bet.
i tried that, it only seemed to add output. and i couldn't raise in much, it started hitting the strings. did i install them wrong? as of now, i'm angry, and considering switching back to emg's. it has this muddyness in every thing i play it through. from my tube amp to my vst amp sim to my little micro cube.
BKP quality is something that is held in highest regard so believe I can understand the frustration of expecting some amazing tone and then something going wrong. The tone IS there, we just gotta figure what's holding it up. From here there some things I would go over-
1-Are they wired properly? Go over this carefully, while I don't have technical knowledge, this seems to be the number one error in getting the tone right....some people here have had problems accidentally wiring their humbuckers and tapping only a single coil instead of both
2-What are the pot values? Again I don't have much techincal vale but the wrong pots can be mega tone-suckers...
I think for humbuckers it should be 500k
3-Did your guitar come equipped with active pickups? Cause if the electronics are set up for active pickups (again the whole pots and wiring thing) and you install passive pickups there are somethings that might need a quick changing, that's most likely the issue.
The boys on this board are very knowledgeable and the answer is probably just a stone's throw away, just give it a day or two (as it is new year's) and someone with more guitar suave will probably be able to walk you through it.
cheers!