FOLD Stereo to Mono
Stereo Width & Mono Utility
Free
FOLD is a free AUv3 audio plugin and standalone app for controlling stereo width and collapsing your mix to mono — with a live phase correlation meter.
FOLD is a stereo width and mono fold-down utility for iOS. Use it as an AUv3 plugin in any compatible host.
FEATURES
Width — Continuously variable stereo width from mono to full stereo. Drag the knob or tap to enter an exact value. Width changes are smoothed to avoid clicks.
Mono — One tap collapses your stereo signal to mono with a click-free ramp. Instantly check how your mix translates to a single speaker, earbuds, or phone.
Output Trim — ±12 dB gain stage after the width processing. Compensate for any perceived loudness shift when narrowing a wide mix.
Phase Correlation Meter — Real-time bar display with a numeric readout. Green means your signal is mono-compatible and safe. Amber indicates partial cancellation. Red flags phase cancellation issues that will cause problems on mono playback devices.
WORKS AS AN AUv3 PLUGIN
Load FOLD in Loopy Pro, GarageBand, AUM, Audiobus, Cubasis, n-Track, or any AU-compatible host on iPhone or iPad. The AUv3 extension exposes all parameters for host automation.
Free. No in-app purchases. No ads. No account required.
Ratings & Reviews
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The developer, Shelbybark LLC, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Shelbybark LLC
- Size
- 11.9 MB
- Category
- Music
- Compatibility
Requires iOS 13.0 or later.
- iPhone
Requires iOS 13.0 or later. - iPad
Requires iPadOS 13.0 or later. - iPod touch
Requires iOS 13.0 or later.
- iPhone
- Age Rating
4+
- 4+
- Copyright
- © 2026 Shelbybark, LLC