ENGS 86 Independent Projects (AB Students)

Degree Program


Year of Graduation


Faculty Advisor

Alexander Hartov, Spencer Topel

Document Type


Publication Date

Spring 2019


The Soundboard is the central component of Syrinx, a synthesizer instrument invented by Spencer Topel. A generated audio signal is transduced through the Soundboard, and by manually adjusting the positioning of its top metal plane, the user can manipulate the encased soundwaves before they are transduced back into a signal and output. My task for this project was to add controller functionality to the Soundboard component by implementing control voltages that carry information about its planar tilt, yaw, and altitude. These voltages can be used to modulate various digital parameters and further affect the sonic output of the instrument. Further, this added functionality allows the Soundboard to operate as a standalone controller for use in various digital instruments. Over ten weeks, I developed a solution that utilizes four pressure-sensing variable resistors in the corners of the Soundboard to generate control voltages between 0 and 5V proportional to the magnitude of depression of each corner. After carefully characterizing the resistive range of the pressure sensors, I designed a voltage divider that maximizes sensitivity and consistency of the voltage response to user depression. My resulting Soundboard adaptation reliably outputs four control voltages that respond linearly to altitude changes of each corner of the top plane, allowing the user to effectively determine its tilt, yaw, and altitude. Lastly, using Arduino to convert these control voltages to MIDI data, I interfaced my Soundboard adaptation with Ableton Live and successfully demonstrated its performance as a standalone controller via simultaneous modulation of four audio effect parameters.