what it does
CHECK shows you where your stereo mix falls apart when summed to mono. not a single correlation number. a spectral curve across 40 ERB frequency bands, updated in real time. you can see exactly which part of the spectrum is out of phase, which part survives, and which part vanishes entirely.
the scoring is bass-weighted (low frequencies count 3x more than highs), because that's where mono collapse actually damages a mix. a score of 60% at 80 Hz means your kick and bass are probably going to fight each other on any system with a single subwoofer.
four controls: SPEED (analysis time constant), FOCUS (frequency range: LOW/FULL/HIGH), BASS (bass weight), ZOOM (display scale). MONO button collapses to mono so you can hear the damage. SIDE button solos the difference signal: everything that disappears in mono, isolated. zero latency. no iLok.
my background is music, not software. i was a touring musician for a long time, had to stop due to illness, and spent three years reading DSP papers and learning C++ from scratch to build the tools i was paying too much for (most of us musicians dont make a lot of money
). CHECK is the diagnostic layer i wanted when i was mixing for release and had no way to know if my wide stereo image was going to hold up on streaming.the KERN architecture uses 40-band ERB filterbanks across all the paid plugins, so the spectral correlation analysis in CHECK is built on the same psychoacoustic model. it's not a standalone curiosity. it's meant to complement the mixing workflow.
CHECK is free - but would love some feedback to make it better.
download: https://kernaudio.io/check/
thank you all!
lots of love!
