The Controller Bank is a number of Controllers that can be loaded quickly in performance mode by pressing one of the numbered buttons. Each numbered button is called a "Quick Slot". The Controller Bank consists of 4 quick slots that you can load any of your saved Controllers into so that you can switch between them without having to go back to the controller screen. This is really useful if you want to control different groups of moovments (controllers) in one session without interacting with the computer.

You can assign a controller to a quick slot in the controller's moovment window. Press More... in the top right corner and then Assign quick slot. You will get a warning if you try to overwrite an existing controller.

The lights below the quick slot numbers will turn red if there is a controller assigned and yellow if that controller is turned on and it is sending MIDI. The LED screen will also light up when the iMoov is sending MIDI. If the controller is selected the number will appear orange and the name of the controller will appear on the screen. In the above example, there are Controllers in quick slots 1 and 2, and the 'delay mix' controller is loaded and active.