How loud should I master for streaming?

There is no single right loudness for a master. Streaming services adjust the volume of every track anyway, so the goal is a master that sounds good at its own level and survives that adjustment. To choose a level, it helps to understand three things: LUFS, true peak and loudness normalization.

LUFS: how loud a track sounds

LUFS (loudness units relative to full scale) measures loudness in a way that follows how we hear, rather than how high the peaks are. It comes from the ITU-R BS.1770 standard, which most streaming services and broadcasters use in some form.

• Integrated loudness is the average across the whole track. This is the number people mean when they say a master is “-14 LUFS”.
• Short-term loudness is measured over a few seconds, and shows how loud the chorus is compared with the verse.

Numbers are negative and closer to zero means louder. A master at -9 LUFS is much louder than one at -14 LUFS.

True peak: the highest point

Peak meters in many DAWs only look at the samples in the file. When the audio is converted back to an analog signal, or encoded to a lossy format such as MP3 or AAC, the waveform between samples can rise above them. True peak, measured in dBTP, estimates those in-between peaks.

A true peak above 0 dBTP can clip on playback or after encoding. A ceiling of about -1 dBTP is common advice for streaming, and some services suggest going lower, around -2 dBTP, for very loud masters, because loud material tends to overshoot more when it is encoded.

Loudness normalization

Most major streaming services measure each track and turn it up or down so that songs play at a similar level, at least when normalization is switched on, which is usually the default.

The reference levels differ between services and change over time. Spotify and YouTube are commonly cited at around -14 LUFS, and Apple Music’s Sound Check at around -16 LUFS. Check each service’s current documentation if a specific figure matters to you.

What this means in practice:

• A louder master doesn’t play louder. A master at -8 LUFS is turned down by several decibels to match the reference. If heavy limiting made it flat and dense, it now sounds flat and dense at the same level as more dynamic songs.
• A quieter master isn’t always turned all the way up. Some services only raise a quiet track as far as its peaks allow, so a very quiet master can end up a little quieter than others.
• Normalization isn’t everywhere. DJ software, club systems, some players and downloads play files at their own level, which is one reason club tracks are often mastered louder.

So how loud should you master?

Choose the loudness that serves the song, within the range that is normal for its genre, and keep the true peak in check.

• Many current pop, hip hop and electronic releases measure louder than -10 LUFS integrated. Acoustic, jazz and classical recordings are often far quieter, and are meant to be.
• If you can’t decide, master so the track sounds good when matched in level with releases you admire, rather than aiming at a number.
• Keep the true peak at about -1 dBTP, and lower if the master is very loud.
• Compare versions at matched loudness. Louder almost always sounds better at first, which is why level-matched listening is the only fair test.

Setting loudness in MasteringKit

• The Loudness control sets how hard the master is pushed. Balanced is a good choice for streaming. Loud, Aggressive and Crushed are for club play and genres where density is part of the sound.
• The Ceiling control sets the true peak limit. Choose -1 dB for streaming, or -2 dB if you use one of the louder settings.
• The Loudness and True peak meters in the workspace measure the 30-second preview. If the preview is the loudest section of the song, the integrated loudness of the full track will usually come out a little lower.

Adjust your master with controls describes every control, including Loudness and Ceiling.

For platform-specific numbers and steps, see Mastering for Spotify and Mastering for YouTube.