Get the J scoop on a P?

[EmaTheMirror]

Disclaimer (as I guess someone might kick off with such a header): I'm well aware there are nuances and variables pertaining to different basses and pickup configurations that cannot be fully replicated, and that's the beauty of musical instruments.

However, in the age of modelling/profiling, IRs and easily accessible hardware/plugins, I was wondering how (and if) you sometimes apply eq corrections and further processing on P basses to get into J bass territory tone-wise, with both pickups full on.
I personally have an idea about which mid frequencies I'd rather scoop and so on, but I'd like to know your say on that without biases.

Even better, is there anyone here who surgically analysed/profiled the spectrum of a J bass with both pickups open and a P bass, to come up with a precise comparison and eq adjustments? Again, keeping in mind that not all Js and Ps sound exactly the same, but I hope you get what I mean.

Just curious.

 

[Jefenator]

My Dingwall Afterburner (with P-like split coils) has this "blue cube" circuit that passively dumps some midrange that can sound harsh when slapping. Supposedly that was incorporated for a while until they developed some more scooped sounding pickups. Doesn't "spank" like a J with a dope set of single coils - but it does help.
I am also very partial to the Aguilar OBP-1 boost-only preamp. It seems to be important for getting a modern slap tone out of my Roscoe Century with Aguilar P/J pickups. My current J/J w/ singles doesn't really seem to need any active help. But when I had a '76 J with that OBP-1 pre and scoopy DiMarzio UltraJazz pickups... watch out!! Total Marcus Miller vibe! (Minus his lyrical virtuosity.)
I can't offer any spectrum analysis, but those are my "caveman" solutions.

 

[NKBassman]

You should be looking for something called a comb filter. It's what's happening when you combine two pickups that are sensing different locations on the string. The frequencies that are filtered depend on the way the string physically vibrates... the two pickups each catch a different part of the strings vibration, and when the two signals are combined together some frequencies are reinforced and some are cancelled out.

The string's vibration nodes change with the length of the string (i.e. which fretted note you're playing), and so the frequencies that are cancelled out are not constant. So a simple pedal EQ offering midrange cut options at one or two frequencies isn't going to do it alone, and a high level analysis of "J VS P" isn't going to tell you anything.

It's called comb filtering because a frequency plot of the output resembles a comb. You can read more here: Comb Filtering: What Is It and Why Does It Matter? - inSync
[Invalid or Expired Link Removed]

 

[NKBassman]

A few folks in this thread describe using the Strymon Deco or a Boss Flanger to achieve a standing comb filter effect:

 

[Nedmundo]

I know this isn't perfectly responsive to your question, but wiring the halves of a P-bass's split-coil pickup in parallel brings it closer to J-bass territory. Fender installed this on its American Series P-basses from approximately 2003-2007, in the form of the S-1 switch in the volume knob. I never used it on my 2004, but it was a potentially useful tone, which scoops out some of the mids.