Today I successfully made and tested a contact mic (pictured above) which will be used to test the resonant properties of the skin of the waffle early next week. Now that I better understand what is going on acoustically in the first waffle prototype, I have started to design a new iteration which uses the unexpected resonating effect to its advantage. The first images above shows the Piezzo transducer (the receiving component of the contact mic) placed on the base of a wine glass. The second image is a visualisation of the sound I received from this microphone whilst ringing the glass with a few rubs and pings towards the end… The top part of the visualisation plots amplitude against time and the bottom colorful part is a spectrograph which visualises the energy present at each frequency band… This particular recording shows the glass is resonating at a fundamental frequency of around 500Hz (between a B and a C) with harmonic overtones at multiples of 500 Hz, and considering the lo-tech assembly of this mic (Piezzo transducer soldered to the end of a cheap microphone cable) the signal is pretty clean! I want to mount an array of these on my structure (in a way which will not affect the resonance of the skinned parts) so that I can acoustically isolate zones + start digitally playing with bits and bobs. Sound to follow in the next post!