Apple Music and Sound Check: the loudness figures Apple publishes.

What is Sound Check?

Apple: “Some songs are created louder than others. For example, you might notice that some stereo songs sound louder than Dolby Atmos songs. Sound Check adjusts the loudness between different songs to play at the same volume” (Apple Support). The iPhone user guide puts it in four words: “Normalize the volume level of your audio” (iPhone User Guide).

How it works, from Apple’s mastering guide: “It first determines the loudness of a track and then stores that information in the file’s metadata. The metadata is then used to raise or lower the volume of each track to prevent jarring volume changes while a device is shuffling songs.” Album playback is handled separately: “Sound Check can also correctly set the volume per album, rather than per song, allowing albums that rely on volume differences between tracks … to maintain their intended volumes” (Apple Digital Masters).

How do I turn Sound Check on or off?

On a Mac: “Open the Apple Music app”, “In the menu bar, choose Music > Preferences or Music > Settings”, “Click the Playback tab”, “Select or deselect Sound Check”. On an iPhone or iPad: “Go to Settings”, “Tap Apps”, “Tap Music”, “Turn Sound Check on or off” (Apple Support). Apple does not say whether it is on by default, so neither do we.

Does Apple Music publish a LUFS target?

Not for stereo. Neither the Apple Digital Masters document nor the Sound Check article contains a loudness figure. Apple’s asset guide does state limits, and they are scoped to immersive audio: for Dolby Atmos and 5.1/7.1 deliveries, “The integrated loudness value must not exceed -18 LKFS, measured per ITU-R BS. 1770-4” and “True-peak level must not exceed -1 dB TP, measured per ITU-R BS. 1770-4” (Apple Video and Audio Asset Guide, version 5.3.19, 8 September 2026).

How much headroom does Apple ask for?

“If the original digital audio data is at 0dBFS, oversampling can result in undesirable clipping. … Our recommendation is to leave at least 1 dB of headroom in order to avoid such clipping” (Apple Digital Masters). The asset guide asks you to check the encode itself: “All files must have been auditioned as encoded by the current Apple AAC encoder … Use these tools to set an appropriate level so that the encode doesn’t show clipping”, and “audible clipping caused by excessive levels to the encoder may be reason for tracks to not be badged and marketed as an ‘Apple Digital Master’”.

Apple also names the consequence of mastering loud: “songs that have been mastered loud will be played back at a lower volume which can make tracks actually sound weaker.”

Which files does Apple accept?

“Apple accepts audio with a sampling rate of 44.1, 48, 88.2, 96, 176.4, or 192 kHz with 16-bit or 24-bit resolution.” For the Apple Digital Masters badge: “Audio must be delivered at 24-bit resolution in an approved format”, and “(Up-sampling and/or bit-padding of 44.1 kHz/16-bit files is not allowed.)” For Hi-Res Lossless: “Sample rates 88.2, 96, 176.4, or 192 kHz. Note that the 44.1 and 48 kHz sample rates don’t qualify as ‘Hi-Res Lossless.’” (asset guide).

A master here returns a 24-bit WAV at your source sample rate, which is the file to give a distributor when 24-bit delivery is asked for.

So what level should I master to for Apple Music?

Apple gives you a headroom recommendation and a clipping test, not a loudness number. Decide the level for the record, keep the encode clean, and know what you delivered: the free LUFS meter reads integrated loudness and true peak in your browser, and the targets page lists every figure any platform publishes.