Recording your own microphone on a Mac is a solved problem. Recording the other person — the voice coming out of your speakers — is where macOS quietly fights you. Here’s how the audio pipeline actually works.
For years the only answer to that was a virtual audio driver like BlackHole and a Multi-Output Device you wired up by hand before every call. It works, and it breaks constantly.
I build MeetingRecorder, a free Mac app that records both sides of a call locally. I’ve run 636 meetings — 284 hours — through it since January, so this is the version of the audio pipeline that survived daily use, not a whiteboard diagram: capturing system audio with ScreenCaptureKit, reconciling two independent clocks into one file, and doing it all without dropping a single sample on the real-time thread.
I started building it after one too many recordings that turned out to be just my own voice — the other side of the call kept coming back silent, and none of the usual fixes stuck for long. I wanted a recorder where system audio simply worked: nothing to route before the call, nothing to remember to undo after it.
The problem in one paragraph
