Kern Audio – Check

Free real-time spectral mono compatibility analyzer. See exactly which frequencies collapse when summed to mono.

What makes CHECK different.

Spectral Correlation Curve

See mono compatibility across 40 frequency bands in real time. not just a single number — a full picture of where your stereo image holds up and where it falls apart.

Bass-weighted score

The score weighs low frequencies 3x heavier than highs — because that’s where mono collapse actually hurts. if your bass drops below 60%, your low end won’t survive a club system.

Frequency-focused analysis

The FOCUS knob lets you zoom into LOW, FULL, or HIGH frequency ranges. isolate your bass mono compatibility or check just the stereo highs.

Instant mono and side monitoring

MONO button collapses to mono so you hear the damage. SIDE button solos the difference signal — everything that disappears in mono, isolated.

System Requirements

• macOS 12+, Intel or Apple Silicon
• Windows 10+, 64-bit
• Any VST3 / AU compatible host