Fixture for matching microphone capsules

thingiverse

This is a fixture I made to match Primo EM172 electret condenser microphone capsules for sensitivity. The speaker is driven by a pink noise signal and the mic capsule under test is recorded in Audacity, then a sample of the recording is analyzed for the rms level. The mic capsules will be used to make a binaural mic to feed my Sony PCM-M10 digital recorder and some other peoples' projects at the Milwaukee Makerspace. Instructions I designed in DesignSpark Mechanical which allows very easy editing to fit whatever speaker and mic capsules you are using. I printed with Coex3D Aqua ABS filament on MegaMax with 0.25mm first layer, then 0.2mm layers. Infill was 20%, no support material and no brim required - the pieces shown are right off the print bed with no clean-up or other messing around. The top and bottom pieces fit together tightly.