I've recently finished building a jazz bass from parts. All strung up the thing sounds great and plays pretty good, except for the E string. Open E sounds all right but any fretted note sound real woofy through an amp and has poor sustain. I've done a good setup on the neck and bridge and my dad did a fret leveling job so there should be nothing wrong with how the bass is able to be set up. It's like it's giving me the tone you'd get with super high action, but it's not high action. If I lower it more it will be too buzzy. I'm using the same strings I've always used on other basses, DAddario XLs. I'm fresh out of ideas.