Description

APU Loudness Limiter is a real-time limiter supporting multiple loudness measurement types simultaneously, including LUFS (Integrated, Short-term, Momentary) and traditional metrics (RMS, Peak, and True Peak). True Peak detection accounts for inter-sample peaks. You can also choose to split or link channels, which is particularly useful for multi-channel audio formats such as Dolby Atmos®.

In addition to standard Threshold, Ceiling, Attack, and Release parameters, the limiter includes look-ahead for preemptive gain reduction. You can select between Natural and Inertial ballistics types, and a Linear Release mode provides a constant rate of gain change rather than a traditional ballistic envelope. A budget system for look-ahead and attack times allows you to adjust these latency-inducing parameters in real-time without causing audio artifacts. Optional dithering is also available.

The real-time visualization displays the loudness of the source, target, and output signals over time. You can switch between a rolling history view and a histogram showing the distribution of loudness levels. Diagnostic tools include breath residual visualization, which shows where the limiter is working hardest to meet the target gain, and a snapshot system for comparing loudness histograms.

The limiter includes presets targeting the loudness and peak requirements of various streaming services and broadcast standards, such as Spotify, Apple, and EBU R128. It also supports external sidechain input for dynamics processing.

Features

• Natural and Inertial limiting behavior
• Linear Release and dithering controls
• Real-time loudness and true-peak limiting
• Integrated, Short-term, and Momentary LUFS monitoring
• Loudness target presets and visualization
• RMS, Peak, and True Peak support
• Threshold, ceiling, attack, release, and lookahead controls

Tech Specs