PLATFORM GUIDE · 5 MIN READ

Apple Music LUFS: how Sound Check plays your music.

With Sound Check on, Apple Music plays songs at about −16 LUFS. Loud masters are turned down, quiet ones turned up. Here's how it works and what it means for your master.

BY OKAN ÇAM · UPDATED

TARGET
−16 LUFS
TRUE PEAK
−1 dBTP
NORMALIZATION
Sound Check
STREAMS
AAC · ALAC

THE SHORT VERSION

  • Apple Music normalizes with Sound Check, to about −16 LUFS integrated.
  • Sound Check is a playback volume change. Apple doesn't re-limit or re-master your file.
  • Loud masters are turned down and quieter ones can be turned up.
  • Listeners switch Sound Check on or off in the Music settings.
  • Apple streams 256 kbps AAC and lossless ALAC. The AAC stream is where overs appear, so keep true peak at −1 dBTP.
  • At −16, a −8 LUFS master is turned down 8 dB: 2 dB more than on Spotify.

How Apple Music's Sound Check works

Sound Check measures each track's loudness with the ITU-R BS.1770 method and plays it at a common level of about −16 LUFS. As on other platforms, it's a gain change at playback: your delivered master stays as it is, and the Music app turns it up or down.

−16 is 2 LU below the −14 used by Spotify and YouTube. So a loud master loses more level on Apple Music than anywhere else: a −8 LUFS master plays 8 dB down, with all of its limiting still in it.

Is Sound Check on?

Sound Check is a switch in the Music app: in the Music section of Settings on iPhone and iPad, and under Music › Settings › Playback on a Mac. Apple has changed the default over the years and many listeners never touch it, so assume part of your audience hears Sound Check and part hears your file at its own level. Make a master that works for both.

AAC, lossless, and why true peak matters on Apple Music

Apple Music delivers your song as 256 kbps AAC, and as lossless ALAC to listeners who turn lossless on. The lossless stream is your master, sample for sample. The AAC stream is rebuilt from less data, and its peaks come out higher than the file you delivered: a master sitting at 0.0 dBFS can clip in the AAC version.

Apple's mastering guidance, part of the Apple Digital Masters program, is to deliver high-resolution masters and check for clipping after encoding, and Apple's free mastering tools include a clip checker for exactly that. The simple rule that covers most cases: keep true peak at −1 dBTP or lower, read on a true peak meter, not a sample peak meter.

Dolby Atmos and Spatial Audio

A Dolby Atmos mix for Apple Music is delivered and measured separately from your stereo master, with its own target: no louder than −18 LKFS integrated, with true peak at −1 dBTP. LKFS and LUFS are the same unit. Measure the stereo master and the Atmos render as two different files with two different targets.

How loud should you master for Apple Music?

The same logic applies as on every normalized platform: a louder master isn't louder, it's turned down with less punch left. You don't need to master to −16 either.

  1. 01Master for the sound, then measure the bounce.
  2. 02Keep true peak at −1 dBTP, and lower for very loud masters: dense material overshoots more in AAC.
  3. 03For a quiet master to reach −16 with peaks still under −1 dBTP, its PLR has to be 15 or less.
  4. 04Compare your master and a reference at −16 LUFS. That's how Sound Check listeners hear them.

Check your master against −16 LUFS

Drop the bounce into the online analyzer. The gap between your integrated value and −16 is roughly what Sound Check does: a master at −10.5 LUFS plays about 5.5 dB down. Choose Apple Music under Hear it on streaming to play it at that level. True peak, with overs marked in red on the waveform, tells you whether the AAC stream is likely to clip.

FAQ

What LUFS does Apple Music use?

About −16 LUFS integrated, applied by Sound Check. Spotify and YouTube use −14, so Apple Music plays loud masters about 2 dB lower than those services.

Should I master to −16 LUFS for Apple Music?

There's no need. Sound Check turns louder masters down and quieter ones up. Keep true peak at −1 dBTP or lower so the AAC stream doesn't clip, and judge your master at −16 LUFS next to a reference.

What is Sound Check?

Apple's loudness normalization in the Music app. It measures each track's loudness and adjusts the playback volume so songs play at a similar level. Listeners can switch it on or off in the Music settings.

What true peak does Apple Music want?

Apple asks for masters that don't clip after AAC encoding. A true peak of −1 dBTP or lower is the simple way to meet that; very loud masters may need more headroom.

Why does my song sound quieter on Apple Music than on Spotify?

With normalization on, Apple Music plays at about −16 LUFS and Spotify at −14, so every normalized track is about 2 dB quieter on Apple Music. Match the two apps' volume and they sound the same.

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