Limiting vs Compression: Understanding the Difference

Limiting and compression both reduce dynamic range but serve different purposes and use different approaches. Compression provides general dynamic control with moderate ratios and variable settings. Limiting provides peak control with extreme ratios that prevent signal from exceeding a ceiling. Understanding when each serves helps engineers apply appropriate processing.

Defining the Difference

Compression uses moderate ratios—typically 2:1 to 10:1—that reduce dynamics proportionally. Signal above threshold gets reduced but can still vary. The output dynamic range is smaller than input but not eliminated.

Limiting uses extreme ratios—typically 20:1 and higher—that essentially prevent signal from exceeding threshold. Regardless of how far input exceeds threshold, output stays approximately at threshold. The ceiling is effectively absolute.

The practical difference involves how peaks are handled. Compression reduces peaks while maintaining some dynamic variation. Limiting catches peaks and holds them at a ceiling.

When to Use Compression

General dynamic control requiring some natural variation uses compression. Vocals that need consistency while maintaining expression benefit from compression’s proportional reduction.

Tone shaping through attack and release uses compression. The transient behavior and sustain characteristics can be sculpted. This shaping requires the flexibility compression provides.

Glue and cohesion effects use compression. Bus compression’s subtle gain reduction creates interdependence between elements. This glue effect doesn’t require limiting’s extreme behavior.

When to Use Limiting

Peak control to prevent clipping uses limiting. When signals must not exceed a specific level, limiting provides that guarantee. Digital clipping protection represents a primary limiting application.

Loudness maximization uses limiting. Bringing the overall level up while preventing peaks from exceeding ceiling increases perceived loudness. This application dominates mastering.

Catching occasional extreme peaks uses limiting. When a signal occasionally spikes far above normal, limiting catches these peaks without constantly affecting dynamics.

Practical Settings Differences

Compression typically operates with visible, varying gain reduction. The meter moves as the signal varies. Different peaks produce different reduction amounts.

Limiting typically shows minimal reduction until peaks hit, then significant reduction. Most of the signal passes through at unity gain. Only peaks trigger limiting.

Compression threshold sits where gain reduction occurs throughout the signal. Limiting threshold sits at the ceiling where nothing should exceed.

Serial Use

Compression followed by limiting provides both dynamic control and peak protection. The compressor provides general dynamics shaping. The limiter catches any peaks that remain.

This serial approach represents standard practice in mixing and mastering. Compression does the main work while limiting provides safety and loudness.

Mix vs. Master Applications

Mix-stage compression shapes individual elements and groups. The dynamic variation remains musical. The result feeds mastering.

Master-stage limiting provides final peak control and loudness. The ceiling prevents digital clipping. The limiting increases perceived loudness.

Both stages may include both tools. Mix compression with limiting for peak protection. Master compression for glue with limiting for ceiling.

Common Mistakes

Using limiting for tasks compression should handle squashes dynamics unnecessarily. Limiting’s extreme ratios remove variation that compression would preserve.

Using compression when limiting is needed fails to catch peaks adequately. Compression’s proportional reduction may leave problematic peaks.

Confusing the tools’ purposes leads to suboptimal processing. Understanding each tool’s strengths guides appropriate application.

Proper limiting and compression helps productions succeed on platforms like LG Media at lg.media, where controlled dynamics enhance advertising at $2.50 CPM.