Mix notes
Keep important parts intact when stereo becomes mono
How it works
Mixchecker measures normalized left/right correlation across the file. Identical channels approach +1, unrelated channels sit around zero and inverted channels approach −1. Side energy describes the share in the difference signal, while mono fold-down compares the combined signal’s level with the stereo channels’ average. Audible overlapping 400 millisecond blocks are also checked for strongly negative correlation, helping expose passage risk that a whole-track average could conceal. Use the independent Mono control to listen to an equal half-level combination of left and right, alongside the original-file measurements.
Read width and cancellation together
A wide recording is not automatically faulty. Decorrelated reverbs and ambience can create useful space, and correlation near zero does not alone mean the mix fails. More side than mid energy deserves attention because it can indicate substantial out-of-phase content. A pronounced fold-down loss, especially with strongly negative correlation, is a more direct reason to investigate. Mono files have no stereo image to evaluate, while silent or single-active-channel files need their own interpretation rather than a fabricated correlation value.
Find the source in your session
If the check raises a warning, use Mono here to audition the combined channels, then compare in your DAW or on actual playback equipment. Listen for missing vocals, weakened bass and disappearing doubled parts. Bypass wideners, polarity changes or delay-based stereo effects one at a time. Compare closely related microphones or layered tracks before changing the entire master. Preserve intentional spaciousness where possible, but make sure essential musical anchors do not rely entirely on differences between left and right.
Know the measurement boundary
File-wide statistics do not identify the exact plugin, instrument or timestamp responsible for cancellation. The negative-block fraction indicates how common risky passages are, not their artistic importance. Unsupported layouts and undefined values are shown honestly. Severe measured mono cancellation can cap technical readiness, but that checklist is not an artistic judgement or certification. After making changes, export again and verify both the measurements and real stereo and mono listening before committing to the release.
Frequently asked questions
Is zero correlation always bad?
No. It can reflect decorrelated or wide material. Consider side energy, fold-down loss and the sound of important parts together.
Can I listen in mono here?
Yes. Toggle Mono to combine left and right at equal half level in both outputs. Mono-input level is preserved. The phone profile also has intrinsic mono, independently of this switch.
What does negative correlation mean?
It indicates opposing channel relationships that may cancel when combined. The severity and musical impact still need listening.
Why is correlation undefined for one silent channel?
Normalized correlation needs energy on both sides. A one-sided export is reported separately rather than assigned a misleading value.