APU Software


Latest plug-in installers and user manuals.

Loudness Meter v1.6.7

Choose your operating system to download the latest installer below.

MacOS Windows User Manual

The user manual above is also available on the live docs site.

Loudness Compressor v1.6.7

Choose your operating system to download the latest installer below.

MacOS Windows User Manual

The user manual above is also available on the live docs site.

Release Notes

Version 1.6.7

  • Support for macOS Mojave (10.14)

    Version 1.6.6

  • Output types: Standard, Bypass, Delta (compressor)
  • Fix output offset in extreme cases (compressor)

    Version 1.6.5

  • Improved preset save
  • Fix missing source knee threshold drawing
  • Fix missing font characters

    Version 1.6.4

  • Default manual reset, with a reasonable general-purpose default loudness range
  • Default breath residual mode enabled

    Version 1.6.3

  • Aesthetic improvements

    Version 1.6.2

  • Fix mono channels when using stereo loudness types

    Version 1.6.1

  • Fix discontinuities at compression curve extremes (compressor)

    Version 1.6.0

  • Presets & Themes management
  • A/B comparison buttons (compressor)

    Version 1.5.2

  • Minor graphical improvements

    Version 1.5.1

  • Fix Logic Pro validation failure
  • Darken the shading a bit outside the visualizer HUD

    Version 1.5.0

  • Improve/fix breath residual feature (compressor)

    Version 1.4.9

  • Support loading from file for analysis (meter)

    Version 1.4.8

  • Many cosmetic & visualizer improvements, configurable bit-depth

    Version 1.4.7

  • Fix mutex double-lock freeze on latency change in Cubase (compressor)

    Version 1.4.6

  • Additional optimizations and re-fix plug-in resize

    Version 1.4.5

  • Fix FLStudio crash on startup (meter)

    Version 1.4.4

  • Fix plug-in resize AU JUCE bug

    Version 1.4.3

  • Reduce overlay redraw overhead

    Version 1.4.2

  • Reduce CPU usage when editor is closed (meter)

    Version 1.4.1

  • Fix rare crash due to text rendering race condition
  • Fix settings apply/discard buttons sometimes enabled unnecessarily
  • Apply look and feel to standalone application audio settings dialog
  • OpenGL performance improvements

    Version 1.4.0

  • Improve sound quality (compressor)
  • Improve performance (especially meter)
  • Smoother history rendering
  • Improve various minor visual elements
  • Fix stereo RMS reset in certain cases
  • Support offline license activation (compressor)

    Version 1.3.1

  • Improve performance via more reasonable default block size (meter)
  • Minor aesthetic improvements

    Version 1.3.0

  • Fixes & improvements to stereo and integrated LUFS
  • Fix for combo-boxes closing themselves.
  • Fix for trial/license activation glitches while offline (compressor).

    Version 1.2.2

  • Updated EULA: Added a commitment to provide unprotected builds in the event the business ceases operations or goes offline, ensuring long-term access to the software for licensed users.

    Version 1.2.1

  • Support LRA, improvements to peak/min history (meter)

    Version 1.2.0

  • Initial release of APU Loudness Meter
  • Bug fixes and quality improvements (compressor)

    Version 1.1.0

  • Fix knee boundary artifacts (compressor)

    Version 1.0.4

  • Eliminate visual discontinuity during history length increase (compressor)
  • Improve target range behavior (compressor)

    Version 1.0.3

  • Reduce pixel shader artifacts (compressor)

    Version 1.0.2

  • Fix license status text not updating in certain cases (compressor)

    Version 1.0.1

  • Enable sandbox safe for audio unit compatibility (compressor)

    Version 1.0.0

  • Initial release of APU Loudness Compressor


This software was developed by APU Software, LLC and is available as VST (windows x64/x86, macOS universal), Audio Unit (macOS universal), or Standalone Application. The software libraries below are utilized for portions of the software:

  • JUCE (cross-platform audio and user interface framework)
  • Boost (header-only algorithms)
  • libebur128 (loudness measurements)

Demo video song credits:

  • Philip Dansor - Bloom (Instrumental), licensed via Audiio.
  • Annasara - A Lifetime Rolls By, licensed via Audiio.