Speaker Layouts

Listening to immersive music on multiple loudspeakers consistently produces an emotional impact and allows sound to propagate naturally within the listening environment. The subtle head movements that occur during listening help the brain to more easily and naturally localize sound sources. As a result, immersive listening with loudspeakers feels highly natural and, over extended periods, may also be less fatiguing and more relaxing. However, various loudspeaker setups exist, depending on the technology and codec used to encode immersive audio, as well as the intended application. Home use (music and film), cinemas, and live sound all have their own specific loudspeaker layouts.

The absolute minimum loudspeaker configuration required for immersive listening consists of five speakers: two at the front (left-right), two at the rear (left-right), and at least one speaker dedicated to reproducing the height layer and/or audio objects. This height speaker is typically positioned centrally above the listener. Different formats provide varying recommendations for optimal listening, often distinguishing between configurations for music and film (home entertainment).

In recent years, numerous formats have emerged, utilizing different numbers of (virtual) loudspeakers.

Virtual loudspeakers are primarily found in soundbars and standalone speaker systems, such as the Amazon Echo and many other devices. Several immersive formats employ either channel-based immersive audio or object-based immersive audio. At present, all major technologies incorporate both approaches to some extent, though this is not always explicitly reflected in their naming conventions.

Chronological overview

2005 //

First presentations of NHK 22.2 (Japan) without the necessary technology to render 24 channels audibly (codec and renderer). Auro-3D 2.2.2 is also introduced without playback technology.

2010 //

Auro-3D debuts its codec and renderer at the AES Conference in Tokyo, making Auro-3D audio playable via Blu-ray (Auro 9.1 for music) and Digital Cinema Package (Auro 11.1 for theaters).

2015 //

Dolby introduces Dolby Atmos for cinemas, featuring object-based audio where the number of speakers depends on room size. Later, Dolby Atmos for home launches with a minimum 5.1.2 speaker setup, expandable to configurations such as 5.1.4, 5.1.6, 7.1.2, 7.1.4, and 7.1.6. Auro-3D introduces AuroMax for theaters, combining channel-based audio with objects, and home formats Auro 13.1 and 11.1 (7+4) for music.

2016 //

DTS launches DTS:X, using speaker layouts combining Auro-3D and Dolby Atmos specifications. The codec and renderer adapt to available speakers, allowing playback on Dolby, Auro-3D, or custom layouts.

2019 //

Dolby's renderer adopts a 7.1.2 bed and objects, allowing full integration of channels and objects at the production level. Speaker configurations expand to include 9.1.2, 9.1.4, and 9.1.6.

Speaker layouts

The naming of loudspeaker configurations generally follows a standardized structure. It typically begins with the name of the developer, followed by a sequence of two or three numerical values separated by periods. These values adhere to a specific pattern: the first number usually indicates the number of speakers positioned at ear level, the second denotes the number of subwoofers, and the third specifies the number of height speakers.

For instance, in a configuration labeled "Dolby 7.1.4," there are seven speakers placed at ear level. These may be positioned at the front, rear, or sides, but this is not explicitly defined by the first number. The second number indicates the presence of one subwoofer.

Finally, the third number reveals that four height speakers are included in the setup. These may be positioned at the front, rear, or sides. In some cases, the last number is incorporated into the first, as seen in "Auro 9.1" instead of "Auro 5.1.4."

Below is an overview of the most common loudspeaker configurations.

Auro 2.2.2

2 front speakers (L/R), 2 rear speakers (L/R), 2 height speakers (L/R front)

NHK 22.2

22 speakers at various heights, including 3 front-bottom speakers and 2 subwoofers

More info : https://en.wikipedia.org/wiki/22.2_surround_sound

Auro 9.1

5 ITU-standard surround speakers, 4 height speakers (front/rear L/R), 1 subwoofer

Auro 11.1 (the first layout with three layers)

5 ITU-standard surround speakers, 5 height speakers (above each surround speaker), 1 Voice of God (VOG) speaker, 1 subwoofer

This was the first layout with three height layers.

Dolby Atmos for home theaters

Number of speakers depends on room size and budget

Dolby Atmos 5.1.2 / DTS 5.1.2

5 ITU-standard surround speakers, 2 ceiling height speakers (L/R), 1 subwoofer

Dolby Atmos 5.1.4 / DTS 5.1.4

5 ITU-standard surround speakers, 4 ceiling height speakers (front/rear L/R), 1 subwoofer

Dolby Atmos 5.1.6 / DTS 5.1.6

5 ITU-standard surround speakers, 6 ceiling height speakers (front/mid/rear L/R), 1 subwoofer

Dolby Atmos 7.1.2 / DTS 7.1.2

7 ITU-standard surround speakers, 2 ceiling height speakers (L/R), 1 subwoofer

Dolby Atmos 7.1.4 / DTS 7.1.4

7 ITU-standard surround speakers, 4 ceiling height speakers (front/rear L/R), 1 subwoofer

Dolby Atmos 7.1.6 / DTS 7.1.6

7 ITU-standard surround speakers, 6 ceiling height speakers (front/mid/rear L/R), 1 subwoofer

AuroMax for home theaters

Number of speakers depends on room size and budget

Auro 13.1 / DTS 7.1.5.1

7 ITU-standard surround speakers, 5 height speakers above the 5.1 surround speakers, 1 VOG speaker, 1 subwoofer

Auro 11.1(7+4) / DTS 7.1.4

7 ITU-standard surround speakers, 4 height speakers (front/rear L/R), 1 subwoofer

Dolby Atmos 9.1.2 / DTS 9.1.2

9 ITU-standard surround speakers, 2 ceiling height speakers (L/R), 1 subwoofer

Dolby Atmos 9.1.4 / DTS 9.1.4

9 ITU-standard surround speakers, 4 ceiling height speakers (front/rear L/R), 1 subwoofer

Dolby Atmos 9.1.6 / DTS 9.1.6

9 ITU-standard surround speakers, 6 ceiling height speakers (front/mid/rear L/R), 1 subwoofer