it works

Well, it's not my normal type of "art" but those are some pretty gorgeous curves. This is the first set of low frequency condenser microphone calibration curves I've measured for an actual purpose. Except for some roughness around 0.05 Hz, the measured spectra are very smooth. This was for some research involving the study of sounds emitted from volcanoes, specifically, Mt. Tungurahua in Ecuador.

The most disturbing part was finding out how different microphone responses can be. These microphones were made by a certain "professional" measurement condenser microphone manufacturer. I'm underwhelmed. The responses vary a huge amount, with -3dB cutoffs varying by a factor of 4 in some cases. I normalized the plots so you can't see it, but the actual sensitivities are quite a bit different from eachother. These are 1 inch microphones, which are the easiest to make, and thus should have the tightest tolerances.

.... hmm.