remember the R value is the max value the pot will give, the '10' pos.........so cutoff freq changes with the spin of the knob.......
I think Q value is probably just as, if not more important than freq.
Reverend guitars also have a bass cut on guitars, maybe find out what value cap they use compare to the .022uF G&L use and go from there.
And we still don't know what guitar or bass and pups you're using?
A vintage bridge pup in an all maple strat is going to be a different story to a deathbucker 5000 in the neck pos. of an LP......
Also, Keegans link is in regard to recording studio EQ which is almost always applied to the recorded audio ie after effects, amps and speakers and the rest of it have done their (huge) part, I'm not sure how much those values apply to the raw guitar signal, also refer to my first sentence again