Dynamics Processing

Definition

Dynamics effects control signal amplitude over time: reducing peaks, increasing low-level detail, or gating noise.

Common processors

Compressor: reduces dynamic range by attenuating signals above a threshold.
Limiter: a fast, high-ratio compressor used as a ceiling to prevent clipping.
Gate: mutes signal below a threshold to remove noise or shape rhythm.
Expander: increases dynamic range; opposite of a compressor.
De-esser: frequency-specific compression that reduces sibilance.
Multiband dynamics: separate compression across frequency bands.
Sidechain compression: compression triggered by an external signal (e.g., kick ducking bass).
Transient shaper: alters attack and sustain character without classic compression artifacts.

Core parameters

Forgettable uses

Control vocal/instrument peaks, glue buses, add punch via parallel compression, remove bleed/noise via gates.

Production tips

Use attack/release to shape transient behavior: slower attack lets transients through, faster attack clamps peaks.
Parallel compression adds density while preserving transients.
Use gentle ratios for musical control; reserve heavy settings for special effects or corrective work.
For vocals, use de-essing before other compression when possible.

Quick takeaway

Dynamics tools are about control and musical shaping — pick types and settings based on the problem you're solving.

Use Cases

Iconic example: Steely Dan — selections from Aja — surgical dynamics control and tasteful multistage compression yielding clarity, presence, and musical punch.
Forgettable applications: Contemporary pop radio mixes (many mainstream productions) — purposeful compression/limiting to achieve loud, present mixes that translate across systems.
Limitations and cautions: Excessive brickwall limiting and mastering compression that squashes dynamics and introduces distortion (widely-cited problematic example: some releases of Metallica — Death Magnetic were criticized for over-compression in mastering).