Setting Pickup Height

[daffy]

OK, I have a couple of questions here...

I have an '81 Ibanez Roadster 924 that is my main bass, and I have done my own set up (I have done lots of guitars before , but this is my first bass setup) - I used the excellent guides posted in the sticky at the top of the forum, as well as the Ibanez and Fender guides, and TuneMyBass.com.

My first problem is that my bridge pickup (a J pickup) has at some time in a previous life been pushed down hard and was wedged. I loosened the screws but had to manually pull it up, but it doesn't seem to want to stay up. Someone suggested that I may need to replace the foam behind it or something - do you think this might be the case? The split P pickups have lots of spring in them still - I can wind them up and down easily.

The second question I have is exactly how to set the pickup height. I have some measurements from the various sites but the GW site says wind em up till they are hot but not too far or they will start to pull on the strings and sound bad.

I guess I want to know:
- how do I set up the pickup heights for a split P, single J pickup system?
- how high is too high and how do you tell? Is there a change in sound?
- do you balance volume across strings, across pickups or both? there's a big difference between P and J at the moment cos the J is so low, and I pretty much don't use it, but I want more treble and attack.
- do you angle the split pickups to follow the fretboard radius (higher in the middle) or adjust them flat?
- Is there any method to setting heights or is it all educated guessing? Can you measure string output or something?

Any help much appreciated - wouldn't be asking if it were in any of the links I can find.

[Kronos]

With the limited knowledge I have, from what I've done to my own basses, check to see if you have springs under the pickup where the screws are. If they're there, then they should help raise the pickup. If not, try to get some. Also, as someone else suggested, replace the foam.

As far as height goes, there is a sweet spot that you want to find where they're not too close (where they'll ruin your sustain) and they're not too far away (low volume). That's as much as I know.

[PilbaraBass]

yes, replace the foam on the J-pup.

raise the pickups until you get those wolf tones or the strings annoying slap off the pole pieces and make popping sounds (and then back them off til it stops). Or until you don't get anymore significant change in tone and volume.

with pickups, you'll get better lows and mids when they're closer (sort of a proximity effect).

I like to have mine as close as possible before I start having problems. If you play with a light touch, that is PRETTY close.

[Alvaro Martín Gómez A.]

Here's what I do for setting pickups' height. The most important thing to notice is that the thinner the string and the nearer to the bridge, the weaker the response and vice versa:

1- Set a proper neck relief.
2- With a 6" steel ruler, I make sure that the measurement from the top of the 12th fret to the bottom of the strings is 3/32".
3- Then I set pickups height as follows: Neck pickup: 5/32" for both bass and treble sides. Bridge pickup: 1/8" (4/32") for both sides.
4- Lower the G string by 1/64" and raise the B string by the same amount.

Coincidentally, I've just bought a bottle of Loctite 242 threadlocker (medium strength) because the screws of my Bongo's pickups keep loosening and the pups are always raising. It turned to be a very annoying thing and that's the best solution for it (according to EBMM customer service).

[daffy]

Many thanks to all who have responded so far, this gives me a lot to go on.

I will have a fiddle on the weekend - right now everyone's gone to bed and it's my bass time :-)