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Dynamics Analyzer: Crest Factor and Dynamic Range

Profiles the dynamic characteristics of an audio file — how much variation exists between quiet and loud moments, and how transient or compressed the material is.

Parameters

Parameter Type Default Description
file_path string required Path to audio file

Example Output

Illustrative summary; MCP responses use structured JSON.

$ analyze_dynamics drums.wav

Dynamics Analysis RMS level: -12.4 dB Peak level: -0.3 dB Crest factor: 12.1 dB Dynamic range: 14.8 dB Complexity: 0.72

What the Numbers Mean

  • RMS Level — The average power level. Represents perceived loudness better than peak. Professional mixes typically sit between -18 dB and -10 dB RMS depending on genre.

  • Peak Level — The highest sample value. Compare to RMS to understand how transient the material is. Drums have high peaks relative to RMS; compressed vocals have low peaks relative to RMS.

  • Crest Factor — Peak minus RMS in dB. Higher crest factor = more transient/punchy. Drums: 12-20 dB. Compressed vocals: 4-8 dB. Over-limited masters: 2-4 dB.

  • Dynamic Range — The difference between the 95th and 5th percentiles of block RMS levels, in dB. Very short files may return null when there are too few blocks.

  • Complexity — Essentia’s DynamicComplexity descriptor of loudness variation over time. It is not bounded to 0–1; compare it across similar material and analysis settings.

Example Prompts

Compression check

How compressed are my vocals? Analyze dynamics of vocals.wav

Transient health

Check if my drums still have good transients after processing

Before/after comparison

Compare the dynamics of drums-raw.wav vs drums-processed.wav — did I kill the punch?

  • analyze_loudness — LUFS-based loudness (broadcast standard) vs dB-based dynamics here
  • detect_problems — Check clipping and other signal problems alongside dynamics
  • full_diagnostic — Includes dynamics analysis in comprehensive measurement

Pro tip

A crest factor below the configured threshold (6 dB by default) raises a low-crest flag. Compare it with the unprocessed drums and listen to the transients before changing compression.