Okay, so I've got a weird problem with my Tune Bass Maniac 4-string... I just re-strung it with TI Flats, and it sounds better than ever before. It's a P/J bass, with an active preamp. On the bridge pup (jazz), the D-string is *markedly* lower in volume than all the other strings. I don't have adjustable pole pieces, but even if I did, the difference is so large I don't think that would be the proper solution. Oddly, the same problem is not present on the neck P pickup. I'm baffled. Any ideas, bass geniuses???