Loudness Meters

The Loudness Meters provide data about an audio file's momentary loudness, short-term loudness, integrated (overall) loudness, and loudness range. You can use these values when mastering for broadcast to ensure compliance with loudness standards (such as the CALM Act).

If the Loudness Meters are not visible, you can select the Show or hide the bottom pane button or choose View > Loudness Meters. For more information, see "Arranging editing views."

The meters display real-time values for each of the following measurements:

The statistics at the top of the tool can display the maximum or last-calculated (current) values. Choose Current, Max, or Reset from the menu at the end of the statistics bar to change the display.

When Loop Playback is selected, the selection must be greater than 2.5 milliseconds to use the Loudness Meters.


Choosing a metering mode

To change the mode of the meters, click the General tab in the Loudness Meters tool, and then choose EBU R 128 or ATSC A 85 from the Mode drop-down list.

The over-target indicators will be triggered if the target values for Integrated and True Peaks meters are exceeded.

Choosing a loudness scale

To change the scale of the meter, click the General tab in the Loudness Meters tool, and then choose EBU +9 or EBU +18 from the Scale range drop-down list.

Choosing a wide range allows you to see low-level signals at the expense of precision display at high levels.

Select Absolute scale (-23 LUFS) if you want to display loudness values as Loudness Units Full Scale (LUFS). When Absolute scale (-23 LUFS) is not selected, all values are expressed as Loudness Units (LU) relative to the selected mode (EBU R 128 Mode or ATSC A 85 Mode).

Configuring peak meters

To toggle the True Peaks meters in the Loudness Meters, select the True peak meter check box on the General tab in the Loudness Meters.

Please note that true peaks are calculated using a higher sample rate than peaks in the Channel Meters for increased accuracy. For more information, see "Monitoring peak levels."

Peak levels may be miscalculated if audio signals are asymmetrical or if a DC offset is present. To enable filtering, select the Advanced tab in the Loudness Meters and then select the True peak blocking filter check box. When True peak blocking filter is selected, peaks are calculated as the maximum of the filtered and unfiltered signals.

The True Peaks meters display levels in dB FS. To change the resolution of the meters, choose a setting from the True peak meter drop-down list on the General tab in the Loudness Meters.