Audio compression reduces the dynamic range of a signal.
Compression is used at all stages of the music production.
It can either be used as a creative and colorating effect, or as a mixing and mastering tool to shape, refine and beef up your mix.
Depending on the technology used in their circuitry, each compressor design has its own specifications and character, making them convenient for particular uses, and bringing very interesting coloration to the sound.
This can make the use of compressors situational and dependant on the producer or engineer's taste.
Here is a quick tour of the Comp FET-76 main panel parameters.
Input
The FET-76 threshold cannot be adjusted.
To increase the compression, you need to raise the Input.
The louder the audio, the more the gain is reduced.
Output
After the compression starts reducing the signal amplitude, you usually need to compensate for the volume loss. To do that, raise the output gain.
Link
When raising the Input knob, the Link control will make the Output knob to move the opposite side.
This acts as a kind of gain compensation, but we would recommend only using it as a guide.
Attack
The amount of time required for compression to fully operate once the input signal goes above the threshold level.
Release
The amount of time required for compression to fully stop operating after the input signal goes below the threshold level.
Ratio
Sets how much the compression affects the sound.
The higher the ratio is, the more the signal will be compressed.
Mix
Blends the Dry and Wet signal.
This is a convenient way to easily achieve "New York" / Parallel compression.
Source
Lets you choose if the compressor input signal (internal), or another track (external) triggers the compression.
Side-Chain Gain
Just like the input knob, this control lets you raise the side-chain gain to increase the compression level.
Detection Mode
Determines if the compression trigger and effect is mono or stereo.
Equalizer
Lets you filter the side chain signal.
Mostly used to take off lower frequencies and avoid, or hone in one, the pumping effect caused by kicks or basses.
Listen
In case you only trust your ears, this let's you hear the side chain signal and the equalization applied on it.
Compression Range
Prevents the compression exceeding a certain amount in dB by restraining the compression range.
The A and B function allows to compare between two distinct snapshots of the loaded preset.
As sometimes the compressors effect can be very subtle, this feature will help you fine tune your settings.
To do that, start from a reference state, and tweak the settings on the comparison state. Then jump from a state to another, to hear the difference without losing your settings on the reference state.
If you want to copy the settings on A to B or vice-versa, select the snapshot you want to copy from (the source) and click over the arrow.
This will make the settings of that snapshot be copied over to the other snapshot.
Note: The arrow is always pointing from the currently selected snapshot (Source) to the other one (Destination).