RC Audio Lab
An RC filter you can hear
- area
- Backend and web
- stack
- TypeScript · React 19 · Web Audio · Vite
- as of
- Sep 2026
Problem
A credit project for Tomas Bata University in Zlín, to make capacitor charging and first-order filters something you can see and hear.
Approach
The filter runs in an AudioWorklet with bilinear-transform coefficients prewarped at the cutoff. The equations update with the substituted values, and you can switch A/B on a guitar riff built from one recorded note.
Result
Playwright tests in Chromium and Firefox render the production audio processor offline and compare the measured amplitude and phase with the maths; the default high-pass must cut the test recording by more than 20 dB.