How to fix your mix with compressors and limiters

Understanding compressors and limiters

At their core, compressors and limiters are dynamic processors that shape the volume of sounds over time. Compressors smooth out the volume of audio by making quiet parts louder and loud parts quieter, creating a more balanced sound. Limiters, on the other hand, serve as a safety net, capping the loudest parts of a track to prevent clipping or distortion. By setting a hard ceiling, limiters allow you to increase the track’s overall volume without risking unwanted distortion.

Adding energy

One of the most valuable uses of compression is to inject energy into sounds that feel flat or weak. For example, applying compression to drums can make them feel more lively. A compressor can bring the quieter parts of a drum hit up to match the louder parts, giving each hit more “weight.”

When working with compressors, key settings like Threshold and Ratio are vital. The Threshold determines the point at which the compressor engages, while the Ratio controls how much compression is applied to sounds that exceed that threshold. By adjusting these settings thoughtfully, you can shape how forcefully the compressor acts, emphasizing or de-emphasizing certain characteristics of the sound.

Managing peaks

While compressors balance overall dynamics, limiters provide precise control over the loudest peaks. Peaks are often caused by transients—sharp, high-energy spikes at the start of sounds, like the attack of a drum. Compressors may not fully catch these quick peaks, which is where a limiter becomes useful. By setting a limiter’s Threshold to an appropriate level, you can ensure no peaks exceed a certain volume, providing a more consistent and controlled sound without changing the character of the instrument.

Combining a compressor with a limiter is a common approach. The compressor smooths out general volume inconsistencies, while the limiter takes care of stray peaks, offering a clean and balanced mix.

Shaping attack and release

Beyond general dynamics control, compressors offer a way to sculpt the finer details of a sound’s structure through the Attack and Release settings. Attack time controls how quickly the compressor reacts to sounds that exceed the threshold, allowing you to either smooth out or emphasize the initial “punch” of a sound. A slower attack lets the transient of a sound pass through before compression kicks in, creating a more pronounced, punchy effect. Conversely, a fast attack reduces the transient for a smoother, softer sound.

Release time affects how long it takes for the compressor to disengage after the sound drops back below the threshold. Short releases create a tighter sound, while longer releases allow the compression effect to sustain, giving the sound a more flowing, continuous feel.

By balancing attack and release times, you can shape not only the initial hit of a sound but also its tail.

Dual compression

Vocals often require extra dynamic control to sit comfortably in a mix. Dual compression is a technique where two compressors are used in sequence, each with different settings. This approach spreads the workload between two compressors, resulting in a smoother, more natural sound than if one compressor were doing all the work.

For instance, the first compressor might catch quick volume spikes with a fast attack and release, smoothing out sudden changes, while the second compressor applies gentler, more consistent compression to maintain overall volume. This layered approach is especially useful for vocals, where clarity and consistency are essential.

Glue compression

Once individual elements are balanced, glue compression helps bring the whole mix together. This technique applies subtle compression across multiple sounds, creating a more unified and cohesive feeling. Often applied on the master channel, glue compression gives a subtle “lift” to the mix, making everything feel like it belongs together.

The goal with glue compression is subtlety. Too much compression on the master can flatten the dynamics, so settings should be dialed back to avoid over-compressing. A good starting point is a low Ratio with moderate Attack and Release times to enhance the track’s natural rhythm and groove.

Maximizing loudness

The final step in most mixes is maximizing loudness without introducing distortion. By setting the limiter’s threshold just below the clipping point (commonly around -1 dB for streaming standards), you ensure that your track remains clean and free from distortion while reaching optimal loudness.

Increasing the gain after setting the limiter threshold can make the track louder, but care should be taken not to push the limiter too hard, as this can introduce unpleasant artifacts. The aim is to find a balance where the track sounds powerful and full without losing clarity.