Set aggregate device settings in Audio MIDI Setup on Mac
For your aggregate device to work correctly, you may need to set the sample rate and drift correction for one or more of its devices.
Set the sample rate
All devices in the aggregate device need to have the same sample rate. The sample rate of each device should match the sample rate of the device chosen from the Clock Source pop-up menu.
In the Audio MIDI Setup app on your Mac, click the name of your aggregate device in the sidebar.
In the right side of the window, click the Clock Source pop-up menu, then choose the device you want to use as the primary clock source of the aggregate device.
In the Sample Rate pop-up menu, choose the sample rate for the device you selected.
Repeat steps 2 and 3 for each device used in the aggregate device, choosing the same sample rate for each device.
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.
If some of the devices in the aggregate device are synchronised through hardware, click the Clock Source pop-up menu, then choose the hardware synchronisation’s primary clock source. Select the Drift Correction tick box for each device that isn’t synchronised through hardware.
If all of the devices in the aggregate device are synchronised through hardware, click the Clock Source pop-up menu, then choose the hardware synchronisation’s primary clock source. Make sure none of the Drift Correction tickboxes are selected.