APU Software – APU Loudness Limiter v3.7.2 for WiN

Free Download The APU Limiter for Windows.  APU Volume Limiter is a real-time limiter designed to support multiple volume types simultaneously. The limiter can be configured to use LUFS, True Peak, RMS, and/or Peak volume types. This allows it to simultaneously target multiple requirements, such as a specific LUFS target and a specific True Peak target. The internal ballistics of the limiter are configurable to work with different volume limiter settings.

Loudness Metering Options

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

The limiter detection circuit can be configured to use any of the following volume types:

Instant

Instant is a short-duration (400ms) LUFS measurement that is useful for handling the dynamics of sound at any given moment. This mode is fast, yet transparent. K-weighting and channel-weighting are applied to the compressor detection circuit, which improves perceptual accuracy.

Short-term measurement

Short-term LUFS measurement (3 seconds) is useful for processing large-scale sound dynamics. Due to the longer duration, this mode is less responsive than instantaneous, 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 with instantaneous measurement.

Integrated

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

RMS

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

True Peak

True Peak loudness measurements are similar to traditional peak measurements, but are more accurate because they take into account peaks between samples. These measurements use a time interval equal to the specified block size (default 1 ms). This mode prevents clipping of peaks between samples, which can be useful in mastering.

Peak

The peak volume types are a standard peaking scheme that operates for a time interval equal to the specified block size (default 1 ms). This is another traditional limiter-style measurement. Technically, this mode is even slightly more sensitive than True Peak, but it is less accurate because it does not take into account peaks between samples.