Loudness levelling
Tracks from different sources rarely have the same loudness. A track mastered for radio can be many times louder than a quiet recording, and without correction the crowd hears every jump. ArenaDirector evens out the loudness of the tracks.
What LUFS is
LUFS (Loudness Units relative to Full Scale) measures how loud a track sounds to a listener, averaged over its full length. A peak meter only shows the highest point of the waveform, so two tracks with the same peaks can differ by 10 dB in loudness, and the louder one catches the room by surprise.
Lower numbers are quieter: -23 LUFS is quieter than -16 LUFS, which is quieter than -9 LUFS.
What ArenaDirector does
The app turns each analysed audio file up or down so that it plays at -16 LUFS. This adjustment is called levelling, and it happens when the app loads the file:
- A track mastered at -9 LUFS becomes 7 dB quieter.
- A quiet track at -24 LUFS becomes 8 dB louder.
Levelling applies to hot buttons, sequences, shows, the play button in the library table, and the preview in the media picker. The preview in the Clip editor plays at the file's own level, because you use it to position cue points.
The analysis runs in the background (see Manage background processing). Until a file has been analysed, it plays at its recorded level without levelling. Once the analysis finishes, a hot button that is not playing picks up its levelling right away, and one that is playing picks it up after it stops.
The app does not level the soundtrack of a video yet. That covers a video used as the audio of a hot button and a video clip in a sequence. These videos play at their own level and ignore the hot button Level. A video you listen to in the library before using it also plays at its own level.
Limits
Levelling has two limits:
- It makes a track louder by at most +12 dB.
- It never makes a track louder than -1 dBTP true peak. True peak is the highest point of the waveform after conversion to analogue, including the points between samples, so levelling cannot cause clipping. This limit only applies when a track is made louder; it never makes a track quieter.
A track that would need more than these limits plays a little quieter than the others.
The bus master volume
A bus's master volume changes the volume of everything on that bus and remains a live fader. Next to it, the Audio screen shows ≈ X LUFS, the level levelled tracks reach at the current setting. At 0 dB, that is ≈ -16 LUFS.
As a rough guide:
- -23 LUFS is the broadcast level.
- About -16 LUFS suits a typical venue PA.
- -14 LUFS is loud.
Hot button Level
A hot button has a Level field on the Sources & triggers tab, below Audio source, with a range of -12 dB to +12 dB. The app applies it on top of levelling. Use it for a jingle that has to stand out, or for a music bed that should sit under announcements. A ≈ X LUFS value next to the field shows the level on a bus at 0 dB.
When changes apply
A new Level takes effect the next time the app loads or plays the hot button's audio. For where the bus sits in the path, see How playback works.