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Loudness

Measure how loud your files are the way broadcasters and streaming services do: integrated loudness in LUFS, loudness range and true peak, to the EBU R128 standard. For Broadcast Wave files, the results can be stored in the file itself.

New to LUFS and true peak? Read Loudness explained first — it covers what the numbers mean and which targets to aim for.

Measure loudness

  1. Select the files to measure — or select nothing to measure all listed files.
  2. Choose Actions › Measure Loudness. (Or click Measure in the inspector's Loudness section.)

Files are measured one after another, much faster than real time; the status bar shows progress and has a Cancel button. Files that already have a result are skipped, so you can run it again after adding files to the folder.

Any file macOS can decode can be measured — WAV, AIFF, CAF, but also MP3, AAC and FLAC.

Read the results

The LUFS and True peak columns fill in as files are measured. Right-click a column header to also show LRA, Max M and Max S. Sort by LUFS to find the loudest and quietest files.

The file list with LUFS, True peak, LRA, Max M and Max S columns, sorted by loudness
All loudness columns, sorted by integrated loudness.

The inspector's Loudness (EBU R128) section shows the full result for the selected file:

ValueUnitWhat it tells you
IntegratedLUFSThe loudness of the whole file — the number delivery specs refer to.
Loudness rangeLUHow much the loudness varies between quiet and loud parts.
True peakdBTPThe highest peak, including peaks between samples.
Sample peakdBFSThe highest sample value.
Max momentaryLUFSThe loudest 400 ms.
Max short-termLUFSThe loudest 3 seconds.
The inspector's Loudness section with Measured and In bext columns

A value of -inf means the file is silent — there is nothing to measure. Integrated loudness and loudness range need a few seconds of audio; very short files may not have them.

Surround and multichannel files

Following the standard, surround channels count slightly more (+1.5 dB) and the LFE channel is left out. The Media Manager reads the channel layout from the file. When a file doesn't say which channel is which, the inspector notes Channel layout unknown — weighted as L R C Ls Rs, the most common order.

Store loudness in Broadcast Wave files

Broadcast Wave (version 2) has fields for loudness. Broadcasters and some delivery workflows read them, so a file can show it meets a specification without being measured again.

  1. Measure the files.
  2. Choose Actions › Write Loudness to Broadcast Wave (bext) — or click Write to bext in the inspector.

The menu item shows how many files will be written. The inspector then shows the stored values next to the measured ones under In bext.

Measure again after editing the audio Stored values describe the audio at the time of measuring. If you edit, normalize or re-bounce a file, measure and write again — otherwise the file carries outdated numbers.

Example: check stems against a delivery spec

  1. Open the delivery folder and choose Actions › Measure Loudness.
  2. Sort by LUFS. Compare with the target — e.g. −23 LUFS ±0.5 LU for EBU R128 broadcast.
  3. Sort by True peak. Anything above the limit (−1 dBTP for EBU R128) needs another look.
  4. Write the values to the files and export a CSV report with the loudness columns visible, as proof of compliance.

How the measurement works

For those who want the details: the Media Manager implements the published standards.