While it’s connected, the iMac’s microphone shows up as an input on the Mac you work on, named like the iMac. Apps there can record or call with it, as with any microphone.
Turn it on
- During setup, tick Microphone on the Sound step.
- Later, choose the display from the Use microphone from pop-up menu in Second Display Settings › Sound.
Choose it in an app
In the app’s audio or microphone settings, choose the input named like your iMac. You can also choose it in System Settings › Sound › Input.
Allow the microphone on the iMac
The iMac asks macOS for its microphone, so macOS asks on the iMac, not on the Mac you work on. It asks when you tick Microphone on the Sound step, when you choose it in Settings, or the first time an app on the Mac you work on listens. If you use the display account on the iMac, it asks when that account starts for the first time. Choose Allow.
If it was denied, the display shows “Allow Second Display to use the microphone in the privacy settings on …” with the iMac’s name. On the iMac, open System Settings › Privacy & Security › Microphone and turn on Second Display. On macOS 12, it’s System Preferences › Security & Privacy › Privacy › Microphone.
Echo
The iMac cleans the sound with macOS’s voice processing, so what its speakers play doesn’t come back through the microphone. It works best when the sound plays on the iMac as well. Sound through the display Mac’s speakers
Cable or network
The microphone works over the cable and over Wi‑Fi or Ethernet.
If something doesn’t work
- The input isn’t in the list. Check that the display is connected and that Use microphone from is set to it in Settings › Sound.
- No sound arrives. Allow the microphone on the iMac, as above.
- Several displays. Each display’s microphone is listed as an input, and an app can choose any of them. Only one at a time is the Mac’s default input: choosing another display in Settings › Sound moves it there.