There’s a tick box in the Aggregate Device options (Audio MIDI Setup app).
Enable drift correction
If the devices in your aggregate device aren’t synchronised using hardware, you need to enable drift correction, also known as resampling, to compensate for drift in the data between devices.
- In the Audio MIDI Setup app
on your Mac, select the aggregate device in the list. - Choose your aggregate device settings.
- If all of the devices in the aggregate device aren’t synchronised through hardware, click the Clock Source pop-up menu, then choose the device with the most reliable clock. Select the Drift Correction tick box for each device.