According to specs on the Fender website, the pole should be farther away from the B string rather then the G string for example.
Here is a copy&paste from them:
Noiseless™ Series
Bass side:
8/64" (3.6 mm) (for the E string of a four stringer though)
Treble side:
6/64" (2.4 mm)
http://www.fender.com/support/basses.php
In general I've found that the output of my B string is a tad lower then the other strings (on my MIA 5 stringer), I compensated that by moving the pickup ever so slightly closer, it's all a matter of trial and error.
Check out their site and go from there..