Dying to hear what you think of the Select by EMG pickup in #12 and perhaps hear a sound clip. I have the same pickup in my short-scale SX and really like it. Cheap but very smooth-sounding!
I was curious about this too, and the PO had installed a nice sprague pot when wiring in the new pickup, so it's not a bad setup on that bass. Plugged into my rig, the pickup sounded really smooth and useable. I have the final strings on the basses for PLEK, so it was a good time to test for tone. There's really nothing wrong with the pickup. I guess I felt it is very close to the stock MIM p-bass pup and a good bit better than the stock SX pickup all around. Good bass extension, pleasant and present highs, and nice "right-down-the-middle" voicing.
So, then, I went and grabbed #4 to play side by side and see what's going on. . . and perhaps it's not fair to compare to a pickup that you custom developed to what you like to hear, but general voicing characteristics aside, (the "chunger" p-bass pup is quite a bit more snarley in the mids), there is a depth, transparency, and harmonic sweetness in the Nordstrand that is not there in the EMG. Even though the pickup is more aggressive in general, it carries more nuance and responds more to variations in finger touch than the EMG. From my recollection, and I don't have #7 with me to confirm, the stock NP4 also had these favorable characteristics but is voiced more scooped than the "chunger" custom version.
So, theoretically, what should have happened with the custom tweak on the p-bass pickup is bass should have increased in the chunger p-pickup but treble should also have increased to a greater extent. I'm not sure what frequency that spike is centered at though. My ear it seems primarily listens in a bass pickup for the bass responsiveness first in preference to the other frequencies. . . making me feel the custom pickup was more "right" than the stock NP4 which I felt lacked a bit particularly on the E string low notes. And having that low end, made me feel the custom pup was more "round" even though in many ways, it is more aggressively voiced than the stock NP4.
I don't know if I'm going to get a chance to track the EMG pups in this batch. I am trying to power my way through them in order to get to the 1st production batch of spec basses. I view the remainder of the SX builds as practice to streamline my process and develop pickups and grading methods. Fixing all of the assembly bugs also gets tiresome after a while. In my seat of the pants test, the Nordstrand offers enough of a tone advantage right off the bat over the EMG that I feel the added cost is substantiated especially since the p-basses are ending up wonderfully affordable on these builds which makes me very happy. Cost-wise, one less boutique pickup really makes a difference. (jazz basses and p/j basses need 2)
I have split my batch into 2 groups. These 4 instruments + whatever I can get done in the next couple of days are going into PLEK ASAP. The machine is down right now though because a new cutter blade is in-bound from Germany, so I will probably not get to it prior to my East Coast trip on the 8th. If machine time opens up, I'm going in.