The entirety of the build is minimal, consisting of a GY-MAX4466 electret ... a capacitor for power line noise suppression. [Stephen] uses various enclosures from Thingiverse for the microphone ...

The ones in microphones ... electret detectable out to 10 inches. This was with the original wax recipe, but there are now much better materials available, like polyethylene. [Jay] heated a a ...