How Physically "Close" Can P'Ups Be?

While I do not have any technical knowledge about this I have seen basses where pickups where basically placed right up against each other, also I would think that if there were any negative effect of this humbuckers would not work.

 

a musicman humbucker is essentially two single coil pickups with large magnets right next to each other, so you'll be fine. with a p pickup close to the bridge I recommend routing a reverse p.

 

Depending on which way they face, and how they are shaped, you could put them side by side. If you do more than 3 pickups, switching and how many to phase or blend together will be the challenge.

 

For PJ set up, there should be no problem getting them as close as physically possible. The sound you'll get could be unique. One way to test this, is set up a "Plank" and mount the pickups the way you want and wire them up the way you like. Then hover the plank with the pickps over the bass in the position you intend to mount them. Pluck a few notes and see how the sound. This way you can experiment with the variety of sounds you'll get before routing out the body.

 

Clever!