Touchpad Parametric EQ

This was a project done with Anthony Mangognia and Alex Spektor while at the University of Illinois at Urbana Champaign as part of ECE 445. Chad Carlson was our TA.

We designed and built a parametric audio equalizer that allowed a user to boost or attenuate a frequency based on their finger position on a custom built touchpad. By applying downward pressure on the pad, the filter Q/bandwidth would change as well. The advantage over traditional equalizers is the ability to quickly sweep the frequency spectrum in real time to gently or aggressively cut or boost a desired frequency.

The touchpad is a low cost design utilizing only 4 pressure sensors, but allows for three control parameters: X (frequency), Y (boost/attenuation), Z (Q/bandwidth). I was responsible for the digital signal processing portion of this project, and implemented an all-pass Metria-Regalia filter.

This project won the Design Award for the Spring 2005 semester.

Applying downward pressure changes filter bandwidth
Metria-Regalia filter
Pressure Sensor Touchpad
Block diagram