Stereo Width & M/S Tool
Encode and decode Mid/Side signals, visualize phase correlation, and reference width-by-frequency guidelines.
Side = (L − R) / 2 — carries stereo-only content. This disappears on mono systems. High side content = big stereo image that collapses to nothing in mono.
SPAN (Voxengo) — spectrum + correlation meter. Free and accurate.
Ozone Imager 2 — stereo width with frequency-dependent control
Brainworx bx_digital V3 — M/S EQ and width control per band
About the Stereo Width & M/S Tool
The Stereo Width & M/S Tool is a free interactive tool for music producers who want accurate answers fast. Whether you're searching for stereo width calculator, mid side processing explained, M/S encoder online tool, this tool gives you real-time results without leaving your browser — and explains the reasoning behind every value so you know what to do with it.
Every tool on MusicProductionWiki is built around one principle: answer the question and explain the reasoning. The Stereo Width & M/S Tool not only calculates — it shows you why those values work, what changes when you adjust them, and what professional producers do differently across genres.
This tool is part of the Frequency & EQ category. It's embedded directly inside the relevant entries in The Producer's Bible — MPW's comprehensive reference library — where it appears in context alongside the theory that explains why each setting works the way it does.
All tools on MusicProductionWiki are free, require no login, and work in any modern browser on desktop or mobile.
Frequently Asked Questions
What is Mid/Side (M/S) processing?
M/S processing splits a stereo signal into a Mid channel (what is the same in both ears) and a Side channel (what is different between ears). This lets you EQ or compress the center and edges of the stereo field independently.
How do I widen a mix without causing phase issues?
Use M/S EQ to boost the Side channel in the high frequencies (above 3 kHz) where widening sounds natural. Keep bass and kick in mono — elements below 100–200 Hz should have minimal side content. Check mono compatibility by summing to mono and listening for cancellations.
What does the phase correlation meter tell me?
A reading of +1 means perfectly mono-compatible stereo. A reading of 0 means no correlation. A negative reading means phase cancellation — the left and right are working against each other. Aim to keep your mix above 0 at all times, ideally above +0.5.