I didn't have any real issue with the standard pickups that came with my Fender PBass but I didn't think an upgrade to the Bartolini 8CBP pickups could hurt. If it could give me a bit more tone then it'd be a good upgrade. I had the luthier/tech at Guitar Center perform the upgrade along with also replacing the standard bridge with a Fender Big Block Bridge. The tech at GC has always done a great job working on my different basses, I've never had an issue and I trust him. Plus he gives me a friends & family discount for his services. The issue I am having is that since the upgrade to the Barts my D and G string seem quieter and have lost their balls. The great thing is that my E and A strings have never sounded better with more growl, and just more balls. I absolutely love the way my E and A strings sound now and are exactly what I wanted to achieve but when I go up to the D string it is noticeably quieter and just lacking in every way. The G string doesn't seem as bad as the D but compared to the E and A strings it too is noticeably quieter and just leaves me wanting more. Is this what I should be expecting from these particular pickups? Could it be an issue from the install that could possibly be corrected?