psychoacoustic mastering plugin
uncover hidden audio
repurpose lossy compression
apulSoft apUnmask is an audio plugin to amplify components of the audio that are psychoacoustically masked by other components.

To achieve this, apUnmask uses parts of the detector algorithm of the opus high-quality audio compression codec. Signal components that would get removed by compression are extracted. These can normally not be heard as they are masked by louder components in time and frequency. apUnmask enables amplifying and sculpting the masked content and adding it to the music.

To shape the frequencies of the extracted signal, it is fed through a linear phase graphical equalizer. It features a bezier curve smoothed frequency response without overshoot.

The result is a form of hyperrealistic audio. The process helps the listener to hear more aspects of the music at the same time. apUnmask can be used as a mastering effect or as an intelligent exciter for single instruments.

Improving Sound Using Audio Compression
Normally, lossy audio compression just removes things. Decades of research have lead to clever algorithms to detect what can be taken away without the listener noticing - all to save on data size. With apUnmask, you can use this research power to your benefit, extracting and amplifying those signals to help the listener's ears hear more.

Suggested Workflow
  • Insert apUnmask on the master track or an individual track to be enhanced.
  • Adjust the master gain until a reasonable amount of delta signal is visible.
  • Toggle the delta listen button to hear the "ghostly" sound what would be removed by the opus codec. This is what normally lives in the shadows of your music.
  • Experiment with the resolution knob to find the most interesting components.
  • Tweak the eq curve to extract and boost the good stuff.
  • Turn off delta listen and enjoy the result.

Main Features

  • Demo version! Download and try in demo mode.
  • Use the power of audio compression algorithms to uncover unheard parts of your music.
  • Linear phase delta signal equalization with graphical editing of the frequency response.
  • Delta listen button: check what would be removed by compression.
  • 3128 samples latency (44.1kHz)
  • Unlimited undo/redo for all actions.
  • Plugin formats: AudioUnits/AAX/VST/VST3 on macOS and Windows
  • Built-in system-wide preset management with import and export of preset files, compatible across platforms and hosts using a human-readable xml file format.
  • Bright & dark color schemes and support for user defined color schemes.
System Requirements
  • macOS 10.11 or newer on an Intel or Apple Silicon CPU (64-bit only).
  • Windows 7 or newer (64-bit & 32-bit supported).
  • A host application compatible with AudioUnits or VST2/3 plugins or Pro Tools (>10.3.5, AAX)
Demo Limitations
  • After 3 minutes, faded bursts of random noise are added to the plugin output.
  • Presets cannot be exported/saved to the preset menu.
  • The first time the plugin is opened in a session, a demo description dialog is presented.