Not to veer too far, but while we're on the topic of Bisonics and positions, I did some more recent experiments in this department with my recently acquired 1962 Gibson EB-0. When I acquired it, it had the factory stock mudbucker in the neck position and an old aftermarket MIJ minibucker in the bridge position. The modifications were very well done and it looked like a factory EB-3. That said, I bought it because I'd been looking for an old EB-0 that was already modded, so that I could drop some Bisonics in it.
The challenge here was with the bridge pickup being in the traditional EB-3 position, very far from the neck pickup. I've never been a big fan of dual pickups that are spaced far apart as it results in a squawky tic-tacky sound (most noticeable in the lower registers). Some like it, but I don't. Since I knew I had to extend the bridge position cavity anyway to get a Bisonic in there, I did so in the neckward direction as far as possible without having the existing cavity peaking out. I was very happy with the result from an aesthetic perspective, but I could still hear a little bit of that squawkiness. So I started thinking... there are so many ways to manipulate tone, let's try some weird stuff and see what happens!
What I ended up finding was that wiring the pickups out of phase (crazy, right? normally sounds terrible in bass context.), in series, but then also sculpting some low frequency out of the bridge pickup via a passive high pass control, got me a very cool, unique, and usably edgy 2-pickup sound. Below is a recording of the results! Unfortunately, hindsight being 20/20, I should have recorded the initial in-phase sound to demonstrate the squawkiness mentioned above. In any case, here are some of the tones on tap now:
1. Neck pickup solo'd (probably the real grail tone on this bass -- anything else it does, I consider to be bonus options)
2. both pickups in series without bridge-pickup lows sculpted (for reference, not a tone I like)
3. both pickups in series with high-pass half engaged
4. both pickups in series with high-pass fully engaged
5. bridge pickup solo'd
*missing is the "both pickups in parallel" mode, which is also selectable with my 4-way rotary switch, but this experiment was focused on "both pickups in series" and how that mode coupled with the high-pass control on the bridge pickup creates a totally new-to-me dual Bisonic sound
**also should note that these are Novak's vintage-spec Bisonics, custom-ordered in a guitar-humbucker size chrome shell format.