The 7.1.2 bed was designed to give users the ability to easily fill the overhead channels with signals that would typically be assigned to a bed. For signals that require front/back panning and more granularity and control, objects should be used.

Some DAWs have subsequently introduced tracks and buses larger than 7.1.2 that utilize a 7.1 bed and four static objects (7.1.4) or 11 static objects. For 9.1.6 tracks and buses additional objects are used for Lw/Rw and LTM/RTM. 

These options add to the creative and workflow choices a mixer can make in selected DAWs. It is transparent from an audio perspective. Mixers should use whatever options makes the most sense for their workflow. As an example, immersive source audio that is captured with microphones capable of 7.1.4 or above are obvious candidates for the use of buses and tracks larger than 7.1.2.

The use of buses and tracks larger that 7.1.2 in the DAW doesn’t alter the maximum bed width of 7.1.2 in the Renderer. However, 7.1.4 and 9.1.6 remain standard Atmos monitoring speaker layouts. We do not anticipate adding beds larger that 7.1.2 as this would present compatibility issues with existing masters as well as downstream encoding processes.