Compressor and limiter

In simple terms, a compressor compresses the louder parts of an audio signal and boosts the quieter parts, resulting in a more consistent level of volume throughout a song.

A compressor works by analyzing the amplitude of an audio signal and then;

• automatically reducing the level when its loudness exceeds a certain threshold (CM.th) - this is also known as downwards compression

or - in the case of the Woovebox compressors;

• automatically boosting the level when its loudness drops below a certain threshold - this is also known as upwards compression

The how strong the volume is boosted when the loudness is below the threshold, is controlled by a compressor's ratio parameter (CM.rt).

The speed by which a compressor kicks in, is governed by its 'attack' (CM.at) setting. Similarly, the speed by which it stops compressing the signal when the audio drops below the threshold, is governed by the 'release' (CM.rl) setting.

Compressors can be used to add warmth, punch, and clarity to an individual Woovebox track. Overall, a compressor is a powerful tool in music production, enabling producers to make their sound more polished and professional.

A limiter can be thought of as a more aggressive compressor; you can achieve a limiter by using a high compression ratios (> 20:1) and short attacks.

Woovebox compressor implementation

The Woovebox compressors/limiters use a mechanism loosely based on the way an analog capacitor or tube works, rather than being a millisecond on/off affair. This gives the Woovebox compressor a slightly smoother, more analog sound/behavior.

Low attack (or decay) values charge (or discharge) the virtual capacitor faster. Whether the capacitor charges or discharges is determined by whether the incoming amplitude is higher or lower than the threshold. The capacitor's virtual state of "charge" is used as measure of how strong the compressor/limiter should crunch the signal. If the capacitor is fed long enough (e.g. signal is above threshold for long enough), the compressor/limiter's ratio should approach the specified/desired ratio. If the capacitor is no longer fed (e.g. signal is below threshold), the "charge" starts dropping off and the compressor/limiter's ratio should approach 1:1 again.

The Woovebox implements upward compression, rather than downwards compression, as it allows for more predictable behavior of the maximum resulting volume; it remains precisely as set by the master volume (M.VoL setting on the GLob page), rather than being signal dependent.

Enhancing transients

Enhancing transients with a compressor in music production means emphasizing the initial, fast-moving part of a sound or a musical note. Transients are the brief moment at the beginning of a sound or musical note that determines its sharpness, attack, and impact. Compressors can be used to enhance the transients of a sound by selectively boosting the initial transient while reducing the rest of the sound.

To enhance transients using a compressor, the attack time is adjusted. The attack time determines how quickly the compressor reacts to the input signal. By setting a shorter or longer attack time, less or more of the initial high-volume sound is passed through before its volume is reduced. This has the effect of emphasizing the start of a sound ('transient') less or more.

By emphasizing the transients of a sound using a compressor, the sound becomes more pronounced and dynamic, allowing it to cut through a mix better. This technique is commonly used in genres such as electronic dance music and hip hop, where a sharp, punchy sound is desired.