M/S Processor 2
AUv3 mid/side stereo processor
Free · Designed for iPad. Not verified for macOS.
Widen a mix, narrow it, decode a mid/side microphone pair or encode for the effects after it. Free AUv3 for GarageBand, AUM and every host, and a standalone app too.
Your stereo image, in two parts.
M/S Processor 2 splits a stereo signal into its mid (what both sides share) and its side (what sets them apart), lets you turn each up or down, mute it or flip its polarity, and puts them back together. Rebuilt from the ground up, it runs as an Audio Unit (AUv3) inside GarageBand, AUM, Logic Pro and any other host, and on its own with an audio interface.
THREE WAYS IN AND OUT
• Inline: left and right in, left and right out. Widen a mix, narrow it, or bring a centered voice forward.
• Decode: record with a mid/side microphone pair, a cardioid facing the source and a figure-8 across it, and hear it as left and right while you play.
• Encode: turn left and right into mid and side for the effects that come after it, and decode them back at the end of the chain.
EVERY PART UNDER YOUR HAND
• A fader for the mid and one for the side, from −48 to +24 dB, each over its own meter.
• Mute and polarity for each, and a link that moves both gains together.
• Swap left and right before anything else, and bypass to compare.
• Input and output meters named by what they carry, L and R or M and S, with held peaks and clip indicators.
• Every control can be automated from your host.
• A notice when the input is mono, which leaves the side with nothing to work on.
MADE FOR EVERY SCREEN
M/S Processor 2 lays itself out for the space it's given: an iPhone upright or sideways, an iPad, iPhone Duo folded or open, and a plugin slot in a host, from GarageBand's compact strip to a whole panel.
QUIET BY DEFAULT
On its own, the app starts with its output muted, so a microphone never feeds back through the speaker next to it.
A LONG STORY
Alan Blumlein described mid/side recording in his 1931 stereo patent, and engineers have relied on it ever since. M/S Processor first came to the iPad in 2013; this is its second life.
From Monolith DSP.
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Information
- Seller
- Ruben Nine Blanco
- Size
- 46.1 MB
- Category
- Music
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - iPad
Requires iPadOS 17.0 or later. - Mac
Requires macOS 14.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
English and 8 more
- English, French, German, Japanese, Korean, Portuguese, Russian, Simplified Chinese, Spanish
- Age Rating
4+
- 4+
- Copyright
- © 2026 Monolith DSP