Compares the phase relationship between two audio files. Useful for checking alignment between multi-mic recordings, parallel processing paths, or duplicate sources.
Parameters
| Parameter | Type | Default | Description |
|---|---|---|---|
| file_path_a | string | required | Path to first audio file (reference) |
| file_path_b | string | required | Path to second audio file (comparison) |
Example Output
Illustrative summary; MCP responses use structured JSON.
$ compare_phase kick-close.wav kick-room.wav
Phase Comparison: kick-close.wav vs kick-room.wav
Overall correlation: 0.42 Polarity match: YES (both positive) Estimated delay: 2.3 ms (room is late)
Assessment: Significant time misalignment causing frequency-dependent cancellation above 250 Hz. Recommendation: Delay kick-close by 2.3 ms to align, or use time-alignment tool in DAW.
What the Numbers Mean
-
Overall Correlation – How aligned the two signals are. 1.0 = perfectly aligned. 0.0 = completely different signals. Negative = one is inverted.
-
Polarity Match – Whether both signals have the same polarity. Mismatched polarity causes cancellation when summed.
-
Estimated Delay – Time offset between the two signals. Positive means the second file is late relative to the first. At 1ms, you get comb filtering starting at ~500 Hz.
compare_phase reports a single cross-file correlation value, not a per-band breakdown. For per-band phase coherence within one file, use analyze_phase.
Example Prompts
Mic alignment
Are my close mic and room mic aligned? Compare phase of kick-close.wav and kick-room.wav
DI vs amp
Check if my DI bass and amp bass are in phase
Parallel path
Compare the phase of my dry vocal and the reverb send – are they canceling?
Related Tools
- analyze_phase – Single-file L/R phase analysis
- analyze_stereo – Stereo width (affected by phase alignment)
- detect_problems – Check other signal problems alongside phase analysis
Pro tip
Audition alignment changes before keeping them. A room mic’s delay may be part of the intended depth, and a single delay estimate can be ambiguous for unrelated or reverberant sources.