I got really annoyed trying to improve the audio quality of YouTube videos, podcasts or even movies. I tried almost all free solutions out there, but none seemed to give good results. So I decided to build my own tool - FreqWave EQ. It's a Manifest V3 browser extension. The architecture has three execution contexts communicating via chrome.runtime messages — a React popup for the UI, a service worker as coordinator, and an offscreen document hosting the Web Audio graph. The audio engine runs in the offscreen document because MV3 service workers can't use the Web Audio API. All state persists via chrome.storage.sync, so settings survive Chrome restart. Screen capture is sticky to the tab it started on. It's completely free and you're welcome to try it out! I would appreciate any feedback!