EMPulse User Manual

Loudness meter and spectrum analyser

1. Insert EMPulse on your master or monitoring bus.
2. Pick or set a Target preset that matches where the audio will be delivered.
3. Play the piece from start to finish and read Integrated loudness against the target line.
4. Check that True peak stays below your ceiling. The readout turns red above −1 dBTP.
5. Switch to the Frequency view to check the tonal balance.

3. Interface overview

The header holds the preset menu, undo and redo, the A/B compare buttons, and the settings menu. Below it, the loudness and frequency buttons switch between the two views.

4. Loudness view

Target

Sets the loudness target line shown on the meter and the history graph:

• streaming: −14 LUFS
• podcast: −16 LUFS
• broadcast: −23 LUFS
• cd / club: −9 LUFS
• custom: your own value, typed into the box next to the buttons

Streaming / Podcast / Broadcast / CD-Club / Custom  ·  Default: Streaming (−14 LUFS)

Custom Target

Your own target value, used when custom is selected. Type a number into the value box to set it.

−30 to 0 LUFS  ·  Default: −14 LUFS

Momentary bar and history graph

The vertical bar shows momentary loudness (the last 400 ms), with a dashed target line, a held maximum marker, and an over lamp that lights when the level goes above the target. The graph beside it scrolls the last minute of short-term loudness so you can see how the level has moved. A time readout counts DAW playback time and resets when the transport stops.

Readout cards

• Integrated loudness: the average loudness of everything measured so far, in LUFS. This is the number delivery targets refer to.
• Short-term: the loudness of the last 3 seconds, in LUFS.
• Momentary max: the highest momentary reading so far, in LUFS.
• True peak: the highest true peak so far, in dBTP. Turns red above −1 dBTP.
• Peak loudness ratio: the gap between the true peak and the integrated loudness, in dB. Higher numbers mean more dynamic audio.
• Loudness range: how much the loudness varies, in LU.

Reset

Clears the integrated reading, the loudness range, all held maximums, the history graph, and the timer. Use it before each fresh measurement.

Button

Pause

Freezes the loudness measurement while the audio keeps playing.

On / Off  ·  Default: Off

Snapshot

Captures the current readings and holds them on the cards, so you can compare against a later reading.

Button

5. Frequency view

The spectrum display runs from 20 Hz to 20 kHz on a logarithmic scale, with a level meter on the right.

Channel

How the spectrum is shown. L + R sums both channels into one curve. L / R shows left and right as separate curves. Mid / Side shows the centre and the edges of the stereo image as separate curves.

L + R, L / R, or Mid / Side  ·  Default: L + R

Smoothing

Averages the spectrum over fractional-octave bands for a smoother, easier-to-read curve. Off shows the raw detail.

Off, 1/12, 1/6, 1/3, or 1/1 octave  ·  Default: 1/6 octave

Analyser Speed

How quickly the spectrum reacts to the audio.

Fast / Medium / Slow  ·  Default: Medium

Peak Hold

Draws a faint second curve that holds the spectrum peaks and lets them decay slowly.

On / Off  ·  Default: On

Reset

Clears the held spectrum peaks and the overload flag.

Button

Freeze

Pauses the spectrum display while the audio keeps playing.

On / Off  ·  Default: Off

Level meter

A stereo peak and RMS meter from −80 to 0 dBFS sits beside the display, with an overload lamp above it. Click Overload to clear the lamp.

Bypass

Freezes all measurement. The audio itself is never affected either way.

On / Off  ·  Default: Off

6. Correlation meter

The correlation meter at the top of the display shows how well the left and right channels agree, from −1 to +1. Readings near +1 mean the channels are in phase and the mix is mono-safe. Readings near 0 mean a wide, decorrelated image. Readings below 0 mean phase problems: parts of the mix will cancel out in mono.

7. Presets and settings

• Preset menu: save and load your own settings, set a default that every new instance starts from, or reset to the factory default.
• A / B: hold two different setups and switch between them. A > B copies the current one across.
• Undo / Redo: step backwards and forwards through changes.
• Settings menu: interface size from 50 % to 200 %, the About panel with your licence information, and licence management.

8. Specifications

EMPulse User Manual · Belgrave Audio Mastering