For the upcoming bee hive concert (FB event), I revised the hive-microphone design from my previous attempts. From the last concert, I learned that one of my designs –attaching the piezo discs directly to the frame– does result in very little sensitivity, also I was interested in more fine-grained control over the capturing process.
I therefore now integrated three piezo discs into one frame, and suspending each from the frame by steel wires which also serve as signal ground. I soldered an additional (twisted) wire to each of the inner parts of the discs to get the signal from the vibrations. All cables run into one plug on the frame. This will hopefully make assembling and opening the hive much easier.
Since the bees avoided direct contact of the combs with the piezo discs themselves, all metal parts of the frame will now be covered with bee wax.