What is Mid/Side processing?

Mid/Side (M/S) processing splits a stereo signal into two components: Mid (the centre/mono content, L+R) and Side (the stereo difference, L-R). By adjusting these independently, you can control stereo width, enhance the centre image, or widen the sides without affecting the centre.

What does width percentage mean?

0% = mono (no side signal). 100% = original stereo width (side signal at unity). 200% = double width (side signal doubled, +6 dB). Values above 100% exaggerate the stereo image but can cause phase issues and reduce mono compatibility.

How does stereo width affect mono compatibility?

When a stereo signal is summed to mono, the Side component cancels out completely. Wider mixes (more Side content) lose more energy in mono. A 200% width mix could lose significant content when summed to mono. Check your mix in mono regularly.

What is a good stereo width for different elements?

Bass and kick: 0-30% (keep centred for mono compatibility). Vocals: 50-100%. Synth pads: 100-150%. Room mics/ambience: 100-200%. Master bus: 100-120% maximum. Always check mono compatibility after width adjustments.

AudioCalcs

Stereo Width Calculator — Mid/Side Level from Width

Calculate Mid/Side levels from stereo width percentage and vice versa.

Stereo Width

0% = mono, 100% = original, 200% = double width

How We Calculate This

Mid/Side Encoding

Mid = (Left + Right) / 2

Side = (Left − Right) / 2

Width Control

Side Level = Width% / 100 (relative to Mid at unity)

At 100% width, Side equals its original level. At 0%, Side is muted (mono). At 200%, Side is doubled.

Mono Compatibility

Mono Energy = Mid / (Mid + Side) × 100%

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates based on standard formulas. Always verify results for critical applications.