Speaker configurations

The loudspeakers are arranged on three levels.

  • Middle level (M): This is where the stereo and surround speakers are located, and where the listener is located.

  • Upper level (U): This is where additional ceiling speakers are located.

  • LFE: Because LFE signals ideally should be perceived evenly throughout the room, a fixed position is not specified.

In the ADM standard, there is also a bottom level (B) (speakers positioned below the listener). Additionally, a second LFE is possible.

Other special speaker positions are:

  • “Voice of God” (T+00): Speakers directly above the listener.

  • Screen edge speakers (M+SC/M-SC): Speakers at the edges of a screen in front of the listener.

Names of speaker configurations

With Dolby Atmos, the designation is in the form M.L.U:

  • M = Number of speakers in the middle level

  • L = Number of LFE channels

  • U = Number of speakers in the upper level

Example: Dolby Atmos 7.1.4 = 7 speakers in the middle level (M), 1 LFE (L), 4 speakers in the upper level (U).

With ADM, the naming is in the form U+M+B:

  • U = Number of speakers in the upper level

  • M = Number of speakers in the middle level

  • B = Number of speakers in the bottom level

Additional speakers such as LFE or T+00 ("Voice of God") must be mentioned separately.

Dolby 5.1 Surround corresponds to this nomenclature: 0+5+0 + LFE.

With ADM, the speaker positions are specified in angles (polar coordinates), starting from the central position of the listener.

  • Elevation: Determines the height of the speaker and is predefined for the three speaker levels: +30 (upper), 0 (middle), -30 (bottom). As a result, only the level designation is used for the elevation.

  • Azimuth: Defines the direction within a plane and is appended to the plane name.

The angle is measured counterclockwise, so the left-hand side has positive azimuth values and the right-hand side has negative azimuth values.

Example: R (right front) = middle level, azimuth -30° = M-30, LTR (Left top rear surround) = Upper level, azimuth +135° = U+135.

The ADM speaker positions are used for assigning the channels of direct channel objects.In Dolby Atmos mode, the corresponding Dolby speaker names are also displayed in brackets.

In the Surround Setup dialog (see “Settings” menu), you will find the corresponding presets for the Dolby Atmos speaker configurations. Detailed information on speaker placement and other configurations can be found on the Dolby website: https://www.dolby.com/about/support/guide/speaker-setup-guides.

Detailed information on other possible loudspeaker arrangements according to the ADM standard can be found in the ITU Recommendation ITU-R BS.2051-3.