Hi, hope this might be useful for you. For visualizing spectrograms look for BatExplorer or use Audacity, also for manipulating sound files. For counting batch data hits, BatClassify Some more bat projects which might be interesting for you Ardubat-batlogger and Bat-Pi

Indeed Shawn, did some tests in the open and came to the same conclusion in differences of the signal strength, will try some more to try to find out how it' s caused and if it can be solved in some way and keeping the box waterproof.

I have same problem but on even a higher frequency of 35.9 kHz as you can see in the Batexplorer picture of a 192 kHz medium gain recording , creating a problem with identifying bat calls. Trying to find out if the frequency and strength of signal is maybe influenced by temperature of the unit.

I use same electronics enclosure with the clear lid, kept the hole for the microphone slightly bigger as the hole in the circuit board and for the moment covered it with part of waterproof band-aid (also ordered the speaker cloth). Replaced the 4 (M3-15mm) screws by hand screws and small rubber o-rings from aliexpress so I don't need any tools to open it. And I made the holes in the flanges a bit bigger so the wire of a "PAW" mini bicycle lock can slip through. It also makes it harder for others to open the box when fitted tight around a branch or so..