ADM

ADM BWF
(Audio Definition Model Broadcast Wave Format) is a file format used for mastering Dolby Atmos mixes. It’s essentially a WAV file containing both the audio and metadata necessary for a Dolby Atmos renderer to recreate the mix, including bed tracks, object tracks, and panning information.
About Dolby Atmos ADM files
by Jan Printz December 2025

The spatial format is from 2012. It contains a lot of channels placed in the socalled bed and/or objects. The ‘bed’ channels (0 – 10) and/or objects channels (0 – 118, but maybe a home Atmos Receiver only can decode up to 16 objects and a lot of cinemas 32… but that is to be determinated) So ADM can also contain only bed or only objects channels.

The bed is normally used for tracks that are more stationary and goes only up to 7.1.2 (the 10 channels where .2 stands for a left and right side ceiling channel). But nowadays most Spatial mixers use a 7.1.4 setup and if they place a track in the front OR back ceiling channel it will go to both front and back due to the .2 side ceiling format. So objects are needed here instead and some use only those.

My approach with Atmos mixes from 50 to 150 original stems/tracks is using a 7.1 bed for the audio at ground level and up to 8 stereo groups for all above ground level; Group 1 for the front ceiling, 2 for the back ceiling, 3 for center ceiling, 4 for the left side ceiling, 5 for the right side ceiling, 6, 7 & 8 for other tracks placed or moving around in 3D space. If there is some tracks placed between ground level and ceiling, they can be duplicated so one goes to the bed and the other to one of the ceiling groups (each with -3 dB or -4/-2 etc)
Because it seems that home receivers can handle up to 16 objects then objects up to 8 stereo groups (or for example 6 stereo and 4 mono) should work fine.

ADM can be downgraded into E-AC3 (Dolby Digital Plus up to 1024 kbps) as a part of mp4 with video. It is downgraded to compressed 5.1 bit with some of the objects added. Here for an example AWS Media Convert can be used.

I can only find one ADM player for computers, but it’s free:

Dolby Atmos Composer Essential from fiedler-audio.
It is a plugin for a DAW like Cubase, Pro-Tool, Logic and the pretty cheap Reaper.

It can play one ADM file at the time by loading the file down in the left corner of the plugin.