M/S Processor 4+

Ruben Nine-Blanco

    • 4.4 • 5 Ratings
    • Free

iPad Screenshots


M/S Processor is an Inter-App Audio and Audiobus-compatible iOS application intended for audio professionals requiring Mid/Side (M/S) signal processing.


While the most common use case for M/S Processor is decoding a M/S signal to L/R, the reverse process (encoding L/R to M/S) is also possible. A third mode, inline mode, is also included. In this mode, a stereo signal is encoded to M/S, and then decoded again to L/R. This 2-in-1 mode is useful for tasks such as narrowing or widening the stereo image, or muting the M or S channels independently for creative or experimental purposes.

Inter-App Audio and Audiobus

M/S Processor is most useful when used together with other Inter-App Audio or Audiobus-compatible apps to process any stereo or M/S audio signal.

Main Features

• Supports MFi or CCK-compatible audio devices with at least 2-input channels
• Supports Inter-App Audio and Audiobus (acting as a filter)
• Encode, Decode, and Inline processing modes
• Peak and RMS metering for input and output channels with peak overload indicator
• Gain (-48dB to +24dB) rotary controls (per channel)
• Linked Gains button
• Swap Channels (M to S, L to R) button
• Mute, and Phase Rotation buttons (per channel)
• Hi-res Retina graphics


Please consider rating or reviewing M/S Processor after each update to help us further develop our app.

What’s New

Version 1.8.5

• Updated draw engine.
• Updated audio engine.
• Added missing app icons.

Ratings and Reviews

4.4 out of 5
5 Ratings

5 Ratings

stevesteele.com ,

Excellent app for my particular need

I score music for film and TV, and I often need to transcribe dense music because a score is not available.

I thought using an mid side decoder could help remove some extremely loud percussion that seemed to wide in the stereo field. No matter how good your ears are, when a mix includes orchestras recorded in large rooms, overdubs of drum machines, sound fx, and there all sent through a final artificial reverb, and you might have to transcribe through an iPhone or iPad speakers, help is welcomed.

I found this MS decoder and used it as an AudioBus effect and was amazed how effective the different modes were at very clearly revealing instruments that were practically undetectable while removing other instruments that, while listening in stereo, made exact transcriptions near impossible.

Each mid and side of the three distinct modes revealed something new.

The app is free and stable. I owe the developer a thank you for making my job easier, and saving me time in the process. That's worth 5-stars.

Developer Response ,

Thank you very much!

Camilo Calvo ,

Really good app

I’m new in this apps for musical production, and now I know what is M/S processing this is really good app for what I Do!

bikdav ,

How Do I Shut It Off When Finished??

I pretty much like this apps functions. BUT, there is no simple way to shut it off when done using. When, I am done using the screen shows that M/S Processor is still recording. Because of this, I can't use it as is. There needs to be a shut off button. OR, there needs to be posted instructions as to how to shut it off when finished.

Developer Response ,

Hello bikdav,

The reason our app shows as recording is because it has the ability to keep processing incoming audio while it is in the background. If you do not longer need to process any incoming audio, feel free to close the app by double-tapping on the home button and then swiping up.

Hope this helps! :-)

App Privacy

The developer, Ruben Nine-Blanco, 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.

Privacy practices may vary, for example, based on the features you use or your age. Learn More

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