Topics covered in this article:
- Logic Settings
- Project Settings
- The Dolby Atmos Music Panner
- Using the Dolby Atmos Music Panner in Logic Pro
- Synchronization with the Renderer
- Template project
This module will cover the basic Logic Pro setup and workflow, both of which will be covered in greater detail in the Logic Pro exercises.
The Dolby Atmos workflow for Logic Pro utilizes the Dolby Audio Bridge to route audio to the Dolby Atmos Renderer. Since there is no native immersive panner capability in Logic Pro, the AU version of Dolby Atmos Music Panner plug-in is used to create Object audio metadata. The Dolby Atmos Music Panner establishes communication to the Dolby Atmos Renderer independent of Logic Pro.
While it is possible to route audio to individual bed channels, Logic Pro does not have a native 7.1.2. panner, so for the purposes of this training an all-Object workflow will be used.
- Navigate to Preferences from the Menu bar: Logic Pro>Preferences> General
- In the Advanced tab, select Enable All
- In the Audio>Devices tab, ensure that Core Audio is enabled, the Output Device is set to Dolby Audio Bridge, and the I/O Buffer Size is set to 1024
- In the Audio>I/O Assignments tab, set the Surround format to 7.1 (3/4.1) and the output routing as shown below.
- Ensure that the settings have been applied and close the Logic Preferences window
- Navigate to Project Settings from the Menu bar: File>Project Settings>General
- In the Audio>General tab, set the Sample Rate to match the Renderer (48 kHz or 96 kHz) and the Surround Format to 7.1 (3/4.1)
- In the Synchronization>General tab, set the Frame Rate to match the Renderer (generally 24 fps)
The Dolby Atmos Music Panner plug-in
The Dolby Atmos Music Panner plug-in creates immersive Object audio metadata and sends that metadata to the appropriate renderer inputs.
Basic functions of the Dolby Atmos Music Panner plug-in include:
- A height enable mode that allows for elevation panning
- Four different height modes including Freeform, Wedge, Dome and Ceiling
- The ability to use the either the “puck” or the knobs to dynamically set the X, Y, Z and size coordinates and values.
- Several different linking modes are provided:
- Mirror X – Mirrors X only
- Mirror Y – Mirrors Y only
- Mirror XY – Mirrors XY
- Copy – copied any action from one channel to the other.
The Panner also features a 16-step sequencer.
The sequencer is engaged via the sequencer toggle.
Once the sequence is enabled, any existing x, y, z settings created when the sequencer is off are ignored. Object size is retained.
The sequencer is locked to the session tempo, and the step duration is determined in the drop-down menu. Options are 1/16, 1/8, 1/4, 1/2, 1, 2, 4, 8, 16, and 32. Each defined sequence path will be completed in this interval.
The individual sequencer steps are where the dynamic Object panning paths are created and edited.
To create and edit the sequence steps and paths:
- Once the sequencer is enabled with the radio button, step 1 will have a white outline.
- Click on Edit to create a path for step 1. The outline will turn red.
- Select one of the four drawing tools to create the dynamic Object path
- The tools are FreeHand, Line, Ellipse, and Rectangle.
- You can optionally use the path trip direction options:
- The path round trip has the Object move along the drawn path and then reverse direction within one step
- The path reverse button has the Object move the opposite direct to which the path was drawn.
- Once a path is drawn, the sequencer will move to the next step, and the step will have a white outline indicating it contains content and can be edited. The next step being created will turn red. Alternatively, any other step can be clicked. The steps don’t need to be written in order, though they will play back in order.
- If the step is to be skipped/disabled, click the step when it has a red outline. It will turn from blue to gray, indicating it will be skipped on playback.
- When all the desired steps are written, click Done.
- To edit any previously created steps, click on Edit, modify as needed, and click Done when finished.
- The Reset button clears all sequencer data. This can also be clicked when in Edit mode.
The color of the drawn paths in the virtual room indicated the status:
- Blue: The object path is active and belongs to a step number block that is currently not editable.
- White: The object path belongs to a step number block that is currently editable. The object path may be active or disabled.
- Gray: The object path is disabled because it belongs to a step number block that is disabled.
- Additionally, the block is currently not editable.
Using the Dolby Atmos Music Panner in Logic Pro
- Insert the Dolby Atmos Music Panner on a track with audio or an instrument loaded.
- The Dolby Atmos Music Panner is located in Audio FX>Audio Units >Dolby Laboratories.
- Assign the track audio output to output 11.
- In the Dolby Atmos Music Panner, establish communication between the Music Panner and the Renderer by entering localhost in the Renderer field – the connection status indicator should be green.
- Use the Object selection drop-down menu to select Object 11.
- To create multiple Objects on different tracks, repeat the steps above, taking care to match the Object and output assignments for each instance of the Music Panner, e.g., assign to Object 12 and set to Output 12.
Synchronization with the Renderer
In order to record a Dolby Atmos master file, the Renderer must be synchronized to Logic Pro. The simplest way to set this up is to use a generated LTC PCM .wav file on an audio track routed to output 129 or 130 of the Dolby Audio Bridge.
There are a number of ways to generate a LTC .wav file. A common source is http://elteesee.pehrhovey.net/ . Ensure that the generated LTC .wav file matches the sample rate of the project. There is a 48kHz 24fps LTC audio file included with the exercise content in the LTC folder.
- Once the LTC .wav file has been generated, create a new audio track by navigating to Track >New Tracks or pressing Cmd+Option+N. In the new track dialog, create 1 mono audio track with no Audio Input, and Audio Output set to Output 129.
- Rename the track to LTC 129 and drag-and-drop the generated LTC .wav file at the start of the timeline.
- In the Renderer, navigate to the Driver tab of the Preferences window and verify that External sync source is set to LTC over audio and LTC input channel is set to 129.
- Toggle the synchronization button On, press Play in Logic, and verify that the Renderer is chasing timecode.
- Note that in order to provide the pre-roll needed for the Renderer to drop into Record, the contents of the other tracks will need to be moved later in the session (generally starting at bar 3 or bar 5 depending on the tempo)
- Set the counter display mode to time by clicking the arrow next to the display
- Move the cursor to beginning and end of the audio in the timeline to determine the in/out points to use in the Renderer. Round to the closest integer value before (for in point) and after (for out point)
(01:00:05:01 for the in point)
(01:01:29:17 for the out point)
- Set the Record in/out points in the Renderer
- Note any offset required based on the LTC timecode. The LTC file provided with the exercise content starts at 01:00:00:00, so the timecode value will be offset by 1 hour.
- Excess pre or post roll in the recorded master can be trimmed on Export of the ADM BWF from the Renderer after the recording is complete.
The Logic Pro template currently included with the Dolby Atmos Music Panner uses a Bed/Object based workflow commonly used in Audio Post Production. For Dolby Atmos Music content creation, use the template supplied in the exercise content titled Dolby Atmos Music Template.logicx.
The template project contains 22 mono Object audio tracks (with the Dolby Atmos Music Panner on each track) routed to outputs 11-32, 16 stereo Object audio tracks (with the Dolby Atmos Music Panner on each track) routed to outputs 33-64, as well as an audio track for LTC audio routed to output 129.
The template is a great place to explore and experiment with Dolby Atmos and Logic, and can be used in the exercises.