Effects Basics

Week 3: Categories of Effects -- Teach the effect categories including which plugins go in each category and which property of sound each category relates to.

Using various effect plugins is a really fun thing to do, as you can alter the sound of any previously recorded audio to make it sound better, more exciting, or to suit any weird needs of your project. There are analogue and digital effects as well; here we're focusing on the digital ones, because nowadays Digital Signal Processing (DSP) is a thing any computer is capable of, but if you want to use analogue effects, you'll have to purchase them one by one, and these pieces of hardware can be pretty expensive.

The main purpose of the effects is the same: to alter the sound; but their methods can be really different. One can categorize the audio effects in many ways, e.g. like this:

• Dynamic Effects: they alter the amplitude of the audio. A Compressor (surprise!) compresses the sound, as it amplifies the loudest parts less than the others, so the volume will be more balanced, while the dynamics of the audio will be reduced. A Limiter is a really hard Compressor, as it doesn't even let the loudest parts exceed a given volume, however, heavy limiting can distort the sound. An Expander is the opposite of a Compressor, as it expands the dynamics of the audio making the quiet parts quieter and the loud parts louder. A Gate is a tool to mute ("lock out") some parts of the audio, so a Noise Gate can suppress the quieter parts completely (e.g. background noise) but won't do anything to the actual sound.
• Delay Effects: they alter the propagation of the audio. A Delay gives echoes to the audio, so any sound can appear again and again and again and again and again, causing feedback or fading out slowly. A Reverb puts the listener into a given sound environment with many echoes of different delay times and volumes and filters, so one can perceive the sound as being reflected from the walls and other surfaces of a bathroom, a hall, a church or even an arena. A Phaser, a Flanger or a Chorus also operates with delays and filters, producing sounds that are hard to describe but easy to recognize. (These three can also be categorized as Modulation Effects.)
• Filter Effects: they alter the timbre of the audio. A High Pass Filter lets the highs through unaltered but suppresses the lows, a Low Pass Filter makes the opposite, and a Band Pass Filter only lets through the sound between given frequencies (i.e. in a given frequency band). An Equalizer (EQ) lets you set your filters in any way you want to, using parameters (gain, frequency, Q factor, gradient, filter type) or a graphic interface (only gain for the given frequency bands).

I think one always has to hear an effect to find out what exactly it does, so I made a short audio clip using the following effects: Compressor, Delay, Reverb, Phaser, Flanger, Chorus, High Pass, Low Pass, Band Pass, respectively.