In the world of recording there are numerous kinds of effects.
However, often there are more terms and details specific to each device than the average engineer would care to learn before jumping in and using the new equipment.
Details are very important, though, and are critical to understanding the basic opperation of all equipment.
So, let’s take a look at threshold based effects and make sure we all have a good understand of how they work and just what everything means.
Some effects are triggered when a sound volume passes a specific point called a threshold.
A good example of a threshold based effect is a gate. A gate will mute a sound (stop it from playing) until the sound reaches a loud enough volume to reach the threshold.
Then the gate will open and the sound will play. Quiet sounds that are below the threshold will not trigger the gate to open and loud sounds that are at or higher than the threshold will trigger the gate to open and the sound to be heard.
This makes a gate very handy if you wanted to be able to hear important loud sounds and automatically mute quiet sounds that are not supposed to be heard, such as low background sounds or noises.
Some effects will become more extreme when the sound passes beyond the threshold and keeps getting louder.
A ratio of 1:1.
For example a distortion effect that starts to sound dirty when a sound reaches a minimal threshold volume will get dirtier as the incoming sound gets louder.
Some effects use a ratio to set the amount of processing that happens once the threshold is passed.
For example, an effect used to control volume (a compressor / limiter) can be set to a ratio of 1:1 (no change past the threshold), a low ratio such as 2:1 (for every 2 dB of volume increase the compressor only allows 1dB of change), a heavier ratio such as 8:1 (for every 8 dB of volume increase the compressor only allows 1 dB of change) or a very heavy compression ratio (called limiting) such as 10:1.