General cause of warbly E string?

[Lorenzini]

I have a great jazz bass with a warbly E string. ALL is perfect but the E.

I've seen this amongst basses, priced anywhere from $100 to $2000. The E string being warbly sounding, more and more the further you go down the fretboard. Do some basses magically have this problem, and others don't? Doesn't make sense to me.

I know that if the pickups are too close to the string it can cause this, but this warbliness is present even unplugged.

It seems that the string, while being the same in volume, or sometimes even higher in volume, isn't as tight and defined. Weak isn't the right way to describe it, nor floppy. Just warbly, with tons of overtones.

And mostly on Fender style instruments.

My question is this - can it be fixed with:

A string tree/retainer on the E and A strings ?

An onboard preamp ?

New pickups ?


I've tried:

New bridge, doesn't do much to improve it.

New strings, if anything it only "deadens" the warbliness, such as going from a roundcore string to a hex core. Still doesn't take it away totally.

I've heard that Nordstrand NJ4SV or NJ4SE (both humcancelling) pickups tighten the sound a lot.

Also I noticed Lakland and Sadowsky use string trees on their basses, probably to improve the B, but it might improve the E too, right?


Any suggestions would be appreciated.