O3A Upmixer - 7.1.2 (Dolby Atmos)

Host Support

Host Type	Support
AAX	Yes
VST2	Yes

Audio

	Channels	Content
Input	10	7.1.2 (Dolby Atmos)
Output	16	O3A

Controls

Mode
LFE Gain

Description

This plugin takes a surround mix prepared for a 7.1.2 system and converts it to third order ambisonics (O3A).

7.1.2 is a standard mix format for beds in Dolby Atmos. It adds two ceiling channels to standard 7.1. Please note that this plugin does not process Dolby Atmos bitstreams directly.

Channels

The channel ordering used is:

Channel	AAX	VST
1	Front Left	Front Left
2	Front Centre	Front Right
3	Front Right	Front Centre
4	Left Surround Side	LFE
5	Right Surround Side	Left Surround Rear
6	Left Surround Rear	Right Surround Rear
7	Right Surround Rear	Left Surround Side
8	LFE	Right Surround Side
9	Left Top Surround	Left Top Surround
10	Right Top Surround	Right Top Surround

Please note that the channel ordering used by Dolby's Atmos RMU may differ. Also, the AAX order above is used when plugins interact with ProTools through the AAX software interface; other parts of ProTools may use a different default order, for instance when exporting to file.

The plugin is available in the O3A Upmixers plugin library.

Controls

Control: Mode

Three modes are supported, "Inferred", "Studio" and "Virtual". Generally, "Inferred" or "Studio" are recommended.

Mode	Description
Inferred	This mode is optimised for use with material that has been mixed using conventional panning techniques, such as equal-power panning or VBAP. The approach produces smooth transitions when sounds pass between speaker locations.
Studio	This mode is optimised for use with material that has been mixed using 'pairwise' panning, for instance in Pro Tool's surround panner. The approach produces smooth transitions when sounds pass between speaker locations. In this mode, the corner layout is always assumed to be Square.
Virtual	This mode simply places each of the main (non-LFE) audio channels in their appropriate speaker direction. This can be worth trying when the mix has not been put together by conventional panning and the channels have a complex phase relationship.

Control: LFE Gain

Audio from the LFE channel can be mixed into the output by setting this dial. It is added to the stream as an omnidirectional signal.

O3A Upmixers