APU Loudness Limiter v3.0.0 for WIN & MAC

APU Loudness Limiter is a real-time limiter designed to support multiple loudness types simultaneously. The limiter can be configured to use LUFS, True Peak, RMS and/or Peak loudness types. This allows you to simultaneously satisfy multiple requirements, such as setting a specific LUFS and a specific True Peak. The internal ballistics of the limiter are adjustable to accommodate the different limiter settings by loudness type.

Loudness Flavors

One of the key features of this limiter is its support for different loudness types. The limiter detection circuit can be configured to use LUFS and/or traditional units of measurement (RMS, Peak). You can also choose to split or merge channels, which is especially useful for multi-channel audio formats such as Dolby Atmos®.

Momentary

Short-term LUFS measurement (400ms), which is useful for processing the dynamics of the sound at any given moment. This mode is responsive, yet transparent. K-weighting and channel weighting are applied to the compressor detection circuit, improving perceptual accuracy.

Short-Term

A longer duration LUFS measurement (3 seconds), which is useful for handling large-scale sound dynamics. Given the longer duration, this mode is less responsive than Instant, but it can be useful for adjusting the overall picture of sound dynamics. K-weighting and channel weighting are applied in the same way as in Instant mode.

Integrated

LUFS measurement of infinite duration. K-weighting and channel weighting are applied in the same way as with instantaneous, as well as both relative and absolute gating. This type of loudness can be useful for continuously adjusting the integrated loudness of a sound to a specific target.

RMS

The default loudness types use a sliding time interval of 150 ms, which can be adjusted. RMS is a traditional loudness measurement that is a good first-order approximation of perceived loudness. This mode does not apply K-weighting or channel weighting to the limiter detection circuit, giving it a more traditional character.

True Peak

True Peak loudness types are similar to traditional peak metering, but are more accurate because they take into account intersample peaks. These metering uses a time interval equal to the configured block size (1ms by default). This mode prevents intersample peaks from being clipped, which can be useful for mastering.

Peak

The peak loudness types are a standard peaking scheme, operating on a time interval equal to the configured block size (default 1ms). This is another traditional limiter-style measurement. Technically, this mode is even slightly more responsive than True Peak, but it is less accurate because it does not take into account intersample peaks.