When using a Behringer USB audio devices with a Mac operating system (OS) with you may wish to 'mix and match' your inputs and outputs. In this example we will show how to set up the XENYX UFX1204 as an input device whilst using the UMC22 for 2 extra outputs. First you need to go into the Audio MIDI setup application on your Mac. Plug in your USB devices. Both devices will be displayed in the list on the left side of the Audio Devices window. Click the + in the bottom left corner and select 'Create Aggregate Device' from the drop down list. All usable inputs and outputs will now be displayed in a list and you can check the boxes of which you would like to use. As you can see in the above image we have set the UFX1204 to use the 16 in channels available as well as the 4 out and we are also using the 2 outputs available on the UMC22 (shown as USB Audio CODEC). We also have the option to rename our new aggregate device by double clicking on the left hand side. It is important to set which device you want to be the clock source to keep the 2 devices synchronised, and also to set a sample rate that both devices can operate at. Once the aggregate device has been setup you can close the Audio MIDI preferences, your new aggregate device will be available for selection in your system preferences and in the audio preferences the DAW you are using.