Does Dolby Atmos make music quieter?
Before we ask the question, why aren't Atmos mixes loud, let's look at how the new immersive format has disrupted the traditional supply chain for releasing commercial records.
In the creative process of making records, there are generally three steps before publishing a record to distribution - Production, Mixing, and Mastering.
Production - The artist and producers write, produce, and record a song.
Mixing - With the song recorded, the production team pulls in a mix engineer to mix the song. This can involve vocal tuning, some arrangement editing, and mixing.
Mastering - Once the final mix is approved, the song is sent to a mastering engineer who uses specialized tools to master the song.
In some cases, the artist acts as the producer and engineer. The end product of this supply chain is a stereo master that gets published and distributed to DSPs (digital streaming platforms).
With DSPs like Apple Music, Tidal, and Amazon supporting Dolby Atmos, an Immersive Mix Engineer is brought into the supply chain.
The Immersive mixer is an offshoot of the (stereo) mix engineer in that he/she receives pre-mastered processed stems from the mix engineer to create a Dolby Atmos mix. These stems contain all the processing of the stereo mix before mastering. The job of the Atmos mixer is to 1. recreate the approved master from stems and 2. create a new immersive mix. Once the Atmos mix is approved an ADM (Atmos Dolby Master) is delivered.
Two masters are provided for distribution. One Stereo Master (-9 LUFS) and one ADM (-18 LUFS). Stereo masters can be published at any loudness, there is no standard. However, ADM files must meet the loudness specification of -18 LUFS with -1dB True Peak.
(Notice how the stereo master is 9dB louder than the Atmos master.)
What happens on playback?
DSPs implement a playback algorithm called loudness normalization that adjusts the playback volume between songs. The idea is to playback any song at a consistent volume, regardless of how loud the mix was mastered. A song mastered too loud will be turned down and a song mastered too soft will be turned up. In the case of Apple Music, this is called "sound check" and is accessible on Mac and iOS devices.
How to turn Sound Check on or off on your iPhone or iPad
Go to Settings.
Tap Music.
Turn Sound Check on.
Does Dolby Atmos make music quieter?
As an exercise, listen to “don’t wanna be your friend” by joan on Apple Music. This is one of my mixes that meets the Dolby Atmos loudness spec (-18 LUFS). When you switch from Spatial Audio (Dolby Atmos) to OFF (Stereo), notice how the Dolby Atmos mix is actually 4dB louder.
Stereo Master (-9 LUFS)
Loudness level 66 dB
Dolby Atmos (-18 LUFS)
Loudness level 70 dB
A Dolby Atmos song will playback about 4-5 dB louder than the stereo version.
You can switch between stereo and Atmos by using Spatial Audio when using Apple hardware (Air Pods Pro and Air Pods Max). When Spatial Audio is enabled, you are hearing the Atmos Mix. When disabled, the music player switches to the stereo mix. Both files playback simultaneously. Making for a seamless user experience.
In Summary
Mixing in Dolby Atmos enables producers, artists, and engineers to create new soundscapes in a 3D audio environment that can be experienced on headphones. As the music industry adopts the immersive format, they'll be able to future-proof their catalog and get exposure through Spatial Audio playlisting.
I’m Alex, a certified Atmos mixer with UMG and WMG. My work spans multi-genres for US labels and across the Atlantic regions. New to Dolby Atmos? Have questions only a pro mixer can answer? Schedule a meeting.
