The loudness of a Dolby Atmos mix is always measured using a dedicated 5.1 loudness re-render. The Dolby Atmos mix is internally re-rendered to 5.1, and that 5.1 signal is measured using standard loudness measurement algorithms.

There are several workflows available for setting up a loudness measurement for Dolby Atmos:

 

Loudness Measurement in Dolby Atmos Renderer application:

Dolby Atmos Renderer application has a built-in loudness measurement. To enable, navigate to Preferences and toggle the Loudness setting:

The Loudness panel can be found in the top right of the Renderer main window. In order to measure loudness in real-time, the Renderer needs a valid LTC connection and sync must be enabled. As you play back a Dolby Atmos mix in a DAW or while playing back a master file in Dolby Atmos Renderer application, loudness will be calculated in real-time. This loudness measurement can be reset and paused via the buttons in the Loudness panel.

Dolby Atmos Renderer application also allows for offline, faster than real-time measurement of a Dolby Atmos Master File. To calculate offline loudness, open the Loudness Analysis window by navigating to Input and Master > Loudness Analysis, or by pressing Cmd+L.

You can analyze the loudness of the entire mix or manually set in and out points. You can also export a loudness report from this window.

 

Internal Loudness Measurement in Dolby Atmos compatible DAWs:

Some DAWs with integrated Dolby Atmos rendering, such as Cubase, Nuendo, Logic, and Studio One—have built-in Dolby Atmos loudness measurement tools that can be typically found in their Dolby Atmos Renderer windows. Please refer to individual DAW user guides for more information.

 

Loudness Measurement with Third-Party Plug-ins.

It is possible to measure the loudness of Dolby Atmos with standard third-party loudness measurement plug-ins. To achieve this, route the 5.1 loudness re-render to an Aux track and insert the desired loudness metering plug-in on that track.

Note that this is the only method for measuring loudness when using the integrated Dolby Atmos Renderer in Pro Tools.

 

Loudness Targets for Dolby Atmos:

For Dolby Atmos music mixes, all labels and streaming services have the same loudness target: -18dB LKFS (integrated), and a maximum true peak level of -1 dBTP. More details on loudness measurement for Dolby Atmos music can be found in the Dolby Atmos Music Master Delivery Specification document, and in the delivery specifications of individual labels and streaming services.

For post-production and podcast content, the target values for loudness and true peak may differ. Please refer to the delivery specifications of the service provider you are delivering to. Delivery specifications of several popular streaming service providers can be found here.