Oh okay, so this is something to work on! Fun.
I built a new pickup disc (I had many extras already, having ordered them for the boundary microphone project) and one interesting thing is that it did not help with the painter’s tape method, but did improve the situation with the plastic clamp I had. I was able to use it in concert with a plastic clamp. Sadly, I do not have a recording, because the sound crew had unrelated but severe equipment issues that show. 🙁
I have not yet tried this new pickup with the 3M Command Adhesive strips, but perhaps I should. Were those to work, it would solve many problems.
Also – and this I find interesting, but confusing – the new, correct-build pickup, while much better with the clamp, did not have as even a bass response as the errant-build pickup (with the extra adhesive and backing tape) did when the errant-built pickup was held in place by hand. Something in the mid-bass went on walkabout. This is also why I want to try again with the command adhesive strips – perhaps that foam will serve the same modulating purpose as the double-sided tape and layer of protective paper. It seems unlikely, but it would be extremely cool if it worked.
It would be interesting to adhese the pickup to a thin plank of material and then place that plank under the bridge. Since my bridges are floating, that could actually be done; the strings would anchor it tightly in place. But they’d have to be very thin material to prevent detuning issues… or perhaps I could get spare bridges and sand them down so they are the correct height with the pickup plank installed!
…that’s an idea.
What would you suggest as a good material for this plank? It should still be thin. We’d be putting it underneath a floating bridge, on the flat face of the instrument, held in place by the bridge which is in turn being held in place by the strings, pressed against the face.