Kaizen DSP

Guides

Fold: a free stereo width plugin for Pro Tools on Mac

By Gabriel Lacroix, Kaizen DSP

Fold changes stereo width differently across the frequency range. Turn its main control one way and the low end moves toward the centre while the highs open outward. Turn it the other way and the balance reverses. It is free, including the AAX version for Pro Tools on Mac, with no payment, signup or licence key.

What Fold does

  • Main control: clockwise narrows low-frequency stereo content and widens the highs. Counterclockwise reverses the contour. The centre position is neutral.
  • Body and Flavour: a tunable resonant Body stage and a choice of Flavour to add colour.
  • Low Cut and Output Trim: to clean up the low end and set the final level.
  • Display: shows the final left and right output spectra around the centre. The degrees shown above the main knob are the Fold position, not a measurement of phase.
  • Appearance: choose a finish, replace the chassis and knob artwork, and import or export an appearance pack. The look is kept separate from your audio settings.

Where to use it

Start on a stereo track, a bus or an effects return. Fold reshapes the differences that already exist between left and right, so results depend on the source. It does not create width from a mono signal (identical left and right channels). If your reverb or chorus return feels muddy in the low end but you like its top, that is a good place to try a little clockwise movement.

Installing Fold in Pro Tools (Mac)

  1. Save your session and quit Pro Tools.
  2. Keep a backup of any existing Fold.aaxplugin if you have installed it before.
  3. Download the Mac AAX installer ZIP from the Fold page (about 211 MB).
  4. Optional: check the file against the SHA-256 value shown on the Fold page with shasum -a 256 "path-to-downloaded.zip" in Terminal.
  5. Extract the ZIP and open the .pkg installer. It may ask for administrator approval.
  6. The installer puts Fold.aaxplugin in /Library/Application Support/Avid/Audio/Plug-Ins. Other plugin formats are not touched.
  7. Reopen Pro Tools and let the plugin scan finish.

Fold needs a 64-bit, AAX-capable version of Pro Tools that supports your Mac. The build minimums are macOS 11.0 on Apple Silicon and macOS 10.15 on Intel; Pro Tools itself may need a newer macOS. Kaizen DSP reports that the installer passed editor, bypass, automation and session recall checks in Pro Tools 25.12.1.133 with offline test audio, and that physical Intel Macs, older macOS versions and real-time hardware audio have not been verified.

To remove it, quit Pro Tools and delete only Fold.aaxplugin from that folder. If it does not load, contact support@kaizendsp.com.

Other formats

  • Mac VST3 (ZIP, manual install), Apple Silicon and Intel.
  • Windows x64 VST3 (ZIP, manual install).
  • There is no Windows AAX, AU or Linux version, so Logic Pro cannot load Fold.
  • Current version: 1.0.0.

Looking for a free chorus in Pro Tools?

Fold shapes width; it is not a chorus. For chorus, Choroboros includes AAX in its Mac installer, and its Green and Purple engines are free with no licence key or time limit, so they work in Pro Tools on Mac. There is no Windows AAX version of Choroboros. The full licence (US$49.99 one time) adds three more engines and Create.