I bought a TUNE TWB63 (6). The sound is OK, but not as good as my passive 4. This bass is constructed better w/ better woods (Maple neck + Rosewood fingerboard / Ovangkol top + Mahogany back) so I expect a little more out of it. It has TUNE stock pickups and I was thinking of putting EMGs or Barts (or something) in it because I have some extra money. Would this be worth it? There will obviously be some improvement in an upgrade, but how much? Also, I'm kinda worried about installing new electronics into a bass that's already got knob holes/control cavity drilled. What if the system I want to use only uses 4 knobs, does the other hole just sit there open? Also, I've heard that passive pups aren't good on 6+ers because the don't capture the full range well. BS?