JJ pups - positioning on a bass and in relation to each other?

[warwickhunt]

I'm sure there is no definitive answer to this... or is there?  

 

I'm contemplating putting a pair of J pups into a Sandberg P bass (shaped/routed) body but as the body is slightly downsized from a 'standard' Fender body I'm left wondering that if I put them in the Fender position they may be visually too close to the end of the neck.  

 

Is there a reason Leo put them where he did (considering Fender moved them in the 70's) and is there a scientific reason or location to place them?  

 

I checked but couldn't find a similar thread on here already.

[mybass]

I'm not fully aware why the original Fender pups were placed in that original position, whether 'scientific' exploration or simply experimenting with different sounds from different placement along the body.

On my self build I generally unless requested, prefer a closer positioning of jazz pickups than Fender and slightly closer to the foot of the bridge. I also bring the P pickup closer to the bridge. Look at Dingwall model with 3 pickups, looks a little overkill but it likely gets all of the Fender type pickup areas covered. The further forward/towards the neck the pickup is, the less 'attack/tightness' string sound is detected whereas nearer the bridge more attack but less 'body', hence two pickups (or 3!) better than one. I also sometimes angle my jazz pups so theres another different look to consider eh?

[warwickhunt]

@mybass good to hear from someone doing self builds and their experience.  My experience with Warwick basses is that they binned the Fender locations for ANY pup combo and even reversed the P pup, so I'd kind of guessed that pups might be placed where the manufacturer fancied them rather than say, relationship to a particular harmonic or whatever!  

[LeftyJ]

20 minutes ago, warwickhunt said:

@mybass good to hear from someone doing self builds and their experience.  My experience with Warwick basses is that they binned the Fender locations for ANY pup combo and even reversed the P pup, so I'd kind of guessed that pups might be placed where the manufacturer fancied them rather than say, relationship to a particular harmonic or whatever!  

Thing is, the harmonic nodes move around while you're fretting. Fender did place his pickups based on harmonic knots (they don't call the P-position the "sweet spot" for nothing), but only relative to the open string. It's more noticeable on his guitars (for example, play a 12th fret harmonic on a Strat or Tele with the neck pickup selected, and you'll barely hear it!) but some thought did go into it. 

 

Here's a cool schematic that I stole from Talkbass that shows the pickup positions relative to a few harmonics: