@armybass The Full Circle seems to have a much more natural representation of the sound than the Bass Max. The Bass Max is more stringy up top (which I always had to roll off a bit with EQ) and more thick and "rubbery" (for lack of a better term) on the bottom end.
In general, my theory of pickups has come to be that there is a spectrum from "under the bass foot/farthest from the strings" to "nearest the bridge crown/furthest from the top" that usually roughly corresponds to a "dark/muffled" sound near the top (i.e. think "Realist") to a "bright/scratchy" sound near the bridge crown (i.e. think "Fishman BP 100"). Pickups like the various bridge wing pickups are in between, but they are usually closer to the crown than to the top, and they also suffer from more variability of pressure on the element since they sound different when you move them.
Pickups like the Full Circle and Yamahiko and Wilson K-1 are closer to the top than the crown, but not so close that they sound muffled and "wooly" like I hear the Realist as being. I think it's probably the ideal spot for a pizz pickup for the kind of sound I'm after.
The one thing that almost all pickups do that I feel has to be mitigated is to excessively amplify the fundamental of the lowest notes. The string length and body size of the double bass acts like a built in acoustic high pass filter for these lowest pitches, so the sound we are accustomed to hearing from an unamplified DB de-emphasizes the fundamental and favors the first partial of the lowest notes. But pickups only sense vibration and don't make this distinction; they simply amplify the frequency they register. For this reason, I think most pickups benefit from a high pass filter.
In my experience, the Full Circle is the pickup that requires the least amount of EQ once the high pass filter is dialed in. For me, using it and the PJB combos that I use, it means that I can set the HP filter and leave the rest set flat, which simplifies things greatly.
