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Phase Coherence Checker

Checks phase coherence: overall and per-band correlation, and polarity detection.

Parameters

Parameter Type Default Description
file_path string required Path to stereo audio file

Example Output

Illustrative summary; MCP responses use structured JSON.

$ analyze_phase stereo-bus.wav

Phase Analysis Overall coherence: 0.84 Polarity: OK (positive correlation)

Per-band Coherence: Sub (20-80 Hz): 0.98 Low (80-250 Hz): 0.92 Low-mid (250-500 Hz): 0.89 Mid (500-2k Hz): 0.83 High (2k-8k Hz): 0.68 Air (8k-20k Hz): 0.55

What the Numbers Mean

  • Overall Coherence — Pearson correlation between the left and right waveforms. Values range from -1 to 1. Positive correlation means shared signal; negative correlation indicates cancellation risk when summed. It is measured separately from the per-band values.

  • Polarity — The polarity flag is set when overall correlation falls below the configured threshold (-0.5 by default). It is a diagnostic clue, not proof of a wiring fault.

  • Per-band Coherence — Phase coherence broken down by frequency range. Low frequencies should be highly coherent (0.9+) for solid bass in mono. Higher frequencies can be lower (0.5-0.8) — that’s normal stereo width from reverb, panning, and stereo effects.

analyze_phase doesn’t measure time delay between channels. To estimate delay between two files (e.g. two mics on the same source), use compare_phase.

Example Prompts

Mono compatibility

Check if my mix is mono-compatible — analyze the phase of mix-stereo.wav

Phase issues

Are there phase cancellation problems in my drum overheads?

Bass check

Is the low end in phase? I want it to translate to mono club systems

  • analyze_stereo — Width and balance measurement (complementary to phase analysis)
  • compare_phase — Compare phase between two different sources
  • detect_problems — Checks clipping, hum, DC offset, and spectral problems

Pro tip

Low or negative bass correlation deserves a mono audition. Check timing, polarity, and stereo processing before deciding whether to narrow the low end.