Audio Effects: Dynamics

Audio effects are used to intentionally alter how a sound, whether it be live or recorded, in order to suit a particular purpose. This is not to be mistaken with sound effects such as those generated in a foley.

These effects are applied to existing sounds for enhancement or any sort of alteration. There are a number of effects at our disposal through just about any part of the signal chain, even from microphones and instruments themselves, down to the DAW through a plethora of plugins. I personally first encountered these in my first digital guitar effects pedal. Reading these highfalutin terms in the manual and display panel stumped and even intimidated me. I can imagine other people feeling the same way. Hopefully, this article can help clear things up a little. Being familiar with and understanding what these effects do is very important in enhancing recordings.

Audio effects can be classified in a few different ways. But for the sake of this course, we will divide them into three groups — dynamic effects, delays and filters.

Dynamic effects are used to manipulate a sound’s amplitude or volume. There are several, but among the ones you will find useful are:

Compressor

This limits or narrows the dynamic range (or the range between the softest and the loudest part of an audio clip). A threshold value is set as a point of reference. Parts louder than this value is attenuated while those that are quieter are amplified. This creates a more even-sounding audio clip.

To illustrate, consider an unedited clip below:

clean-1

 

After compression is applied with a threshold of -7dB, even though the effect on the actual sound is still subtle, you will notice how the waveform has a more consistent amplitude across the clip.

compressor-1

 

Hard Limiter

This is much like a compressor, albeit a more forceful one. Whereas a typical application of compression provides a significant allowance above and below the threshold, a hard limiter, not so much.

limiter-1

 

Gate

This effect completely cuts off amplitude when it goes below a threshold. This is very useful for reducing noise, but is also commonly used for triggering other events in a DAW session or project.

 

Distortion

When a signal is amplified to the point where it gets so loud, the waveform gets clipped, distortion occurs. Below is our clip after being heavily distorted (warning: it’s loud).

distortion-1

While the above clip is obviously unpleasant to listen to. Distortion can sometimes work for you. Does anyone have any idea where or when?