Stereo Field & Phase Meter
Check your stereo width, phase correlation and mono compatibility before release. 100% in your browser, nothing uploaded.
How to read stereo width and phase correlation
Phase correlation is a single number that describes the relationship between your left and right channels. At +1 the two sides are identical — the track is effectively mono. Around 0 you have a wide, spacious stereo image. Below 0 the channels are fighting each other, and when a system sums them to mono, the out-of-phase parts cancel and disappear. That's the trap: a mix can sound enormous in headphones and then lose its bass or a widened synth the moment it plays on a phone, a Bluetooth speaker or a club rig, all of which collapse to mono. This meter reports overall correlation plus stereo width, and — crucially — the correlation of the low band and high band separately, because that's where the real risk lives.
The practical rule most engineers follow: keep the bass and lead vocal centred and mostly mono, and save widening for higher-frequency elements like cymbals, pads and reverb tails. A low band that drops toward or below zero correlation is the classic cause of a kick or bassline that "disappears" in mono. Everything runs locally with the Web Audio API, so it works on unreleased demos and private stems, nothing uploaded. If the meter flags a mono problem, the fix is mono-ing the lows and controlling side energy — which TrackGleam's free mastering handles automatically, keeping the low end mono-safe while preserving the width up top.
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FAQ
What is phase correlation?
How similar the left and right channels are: +1 (identical/mono), 0 (wide stereo), -1 (fully out of phase). +1 to +0.3 is safe and mono-compatible; below 0 means parts of the mix cancel out in mono.
Does this upload my audio file?
No. The file is decoded and analysed entirely in your browser with the Web Audio API — nothing is sent anywhere. It works on unreleased demos and private stems.
Why does mono compatibility matter?
Clubs, phones, Bluetooth speakers and many TVs sum to mono. If your low end or a widened element is out of phase, it cancels when summed and vanishes — so a track that's huge in headphones can lose its bass on a phone.
What is a good stereo width?
There's no single number — genre and arrangement decide it. Aim for width that survives mono: keep bass and vocal centred, widen higher-frequency elements. Separate low/high correlation tells you if your width is safe.