Need a high output p pickup that is quiet

It's not just radio-frequency:

(Radio-Frequency Interference) RFI vs. EMI (ElectroMagnetic Interference)

G&L SB-1 MFD:

Pickup - SB-2 / SB1 MFD

 

While I have not used the split-coil MFD, I have used the full-length MFD humbuckers in the ASAT & L-2000, & they have the most output of any passive pickups I've ever heard.
Although, the Power-Pole pickup in my GSR100EX comes close.

 

Nailed it on the first post. The bucker in the L1000 or Kiloton would get it done too. But the MFD pickups are really hot.

 

All of them. Theyre humbuckers. Just make sure your wiring is sound.

I've never had a noisy P pickup. I've never had any pickup noise that re-wiring couldn't fix. But, I will always suggest an NP4A for a split. I have yet to find anything better.

 

If you want high output the neodymium PBXN from Entwistle is a beast (sounds great too, and it's pretty cheap but don't let that put you off).

 

This is their website, but it seems their neodymium pickups are not currently available from them:
Entwistle Custom Pickups --- Home

However, you can still find them on some vendors (Europe, as it's a UK company, but even factoring the shipping costs you end up with a great pickup for not much money at all... I've got one that I am not using at the moment, but I want to hang on to it )

ENTWISTLE PBXN (BK)

I see that they appear on ebay.co.uk frequently too.

The pickup covers they come with have big mounting ears which may not fit all pickguards, but they're not glued so you can use any other pickup covers you want. The poles are adjustable so it's very easy to get perfect string to string balance.

 

+1 to the G&L MFDs. The P versions are the hottest passive pickups I’ve used (even more output than their larger humbuckers in my experience), and most importantly they sound fantastic!

 

I have a bass with two of those Dimarzio pickups, and they are both dead quiet soloed. Is all the wiring secure?

The only noisy P pickup I have experienced was in a Univox where the connector wires for the two halves of the pickup were attached the wrong way round.

 

Yep, a P bass with two sets and 500k pots. The bass isn't shielded either. And it is super loud!