Bass! How low can you go? That’s some dancey-wancey lyric for someone to look up. I’m unconvinced; 35″ scale or not. I already find the low B a little flobbly and testing some of my amps (or, more accurately, drivers) range to the limit. What’s the frequency, Kenneth? B is 30Hz so F# must be in the sphinctre-opening category.

Tim, when you say “neck P-up” are you intending on using the pickup cavities already in the body or actually go closer to the neck?

Odd that the pics don’t work. I tried to edit the post, but no joy either. When I c+p the URL into my header, I can see your pics fine 😕

Anyhoo, I don’t think you have to worry too much about the pup. An open B is (IIRC) about 30Hz so you can keep that in mind but, for instance, Fender’s Musicmaster Bass used a Telecaster pup and Ric’s original “toasters” were also guitar pups (although the Ric brightness is a putoff for some). As you mention, the likes of Dunkmore Semen have little graphs so you could choose a lo-emphasized pup. The other thing is that a B is flobbier and will vibrate over a wider distance than the E would. I doubt if this is a problem with the split-coil’s two polepieces per string.

With a choice of pups to install, though, I’d be tempted to aim for the likes of Dunkmore’s quarter pounder (fatter polepieces and more bass freq emphasis) or Dimarzio’s Split-P (blades rather than polepieces, and a wider eq range than the std pup). I actually owned a new Split-P for a while, but changed my mind about my bass design and flogged it still in the box so I have no idea how it sounds, unfortunately. You could have a look at H-C’s bass pup user reviews, I suppose.