And when it breaks? Now you know exactly where to start looking.
A virtual driver installs a kext that appears to the system as a real audio device. But instead of talking to hardware, its Read() method writes audio into a circular buffer. Another app reads from that buffer. macbook audio driver
| Symptom | Likely Layer | Terminal Check | | :--- | :--- | :--- | | Red light from headphone jack (optical SPDIF stuck) | HDA codec state machine | sudo kextstat \| grep HDA | | Audio works after reboot but stops on wake | Power management (kext) | log show --predicate 'subsystem == "com.apple.audio"' | | Zoom audio works, Spotify doesn't | Core Audio mixing graph | sudo launchctl kickstart -k system/com.apple.audio.coreaudiod | | No sound, but volume keys change UI | Kernel to user-space IPC | sudo sysctl -a \| grep audio | And when it breaks