Glossary
System audio
The sound the Mac itself plays, from any app, captured as part of a screen recording. macOS records it only through the screen capture API, and not every recorder asks.
System audio is whatever the Mac is playing: a video in a browser tab, a notification, the app being demonstrated making a sound, a call. It is distinct from the microphone, which hears the room, and a screen recording can carry either, both or neither.
Why it is awkward on a Mac
For most of macOS's history there was no way for an app to hear what the Mac was playing. QuickTime Player and the Cmd+Shift+5 toolbar still cannot: they record the screen and a microphone, and the sound from the speakers is not on offer. The workaround was a virtual audio device such as BlackHole, routed through Audio MIDI Setup so the recorder could listen to it as though it were a microphone. It works, and it is fiddly, and it is how most guides on the subject still read.
Since macOS 13 the screen capture API can hand an app the system's audio alongside the frames, and a recorder built on it can record the Mac's sound with nothing to install. Not every recorder asks for it. The post on recording a Mac with internal audio goes through which do.
Keep it on its own track
The useful version of system audio is a separate track from the microphone. Mixed together at record time, a notification chime over your sentence is in the recording for good. Kept apart, it can be turned down or dropped afterwards while your voice stays. Prequel records the two separately, and the Audio panel has an include switch and a level for each.
Related terms
- Frame rateThe number of still pictures a video shows each second, written as fps. Screen recordings are usually made at 30 or 60.
- Picture-in-pictureA camera feed drawn as a small window over a screen recording, so the viewer sees the presenter and the screen at the same time.
- ResolutionThe size of a video's picture in pixels, width by height. 1080p is 1920 by 1080; 4K is 3840 by 2160.
- Retina and HiDPIA display that draws each point of the interface with four physical pixels, so text is sharp. A screen recording of one is twice the width and height it looks.
Questions people ask
- Does QuickTime record system audio?
- No. QuickTime Player and the Cmd+Shift+5 toolbar record the screen and a microphone. Capturing the Mac's own sound with them needs a virtual audio device such as BlackHole routed through Audio MIDI Setup.
- Can I record system audio and my voice as separate tracks?
- With a recorder that keeps them apart, yes. Prequel records the microphone and system audio as two tracks, so each can be included, dropped or set to its own level in the editor afterwards.