Compression is a powerful tool to help you get the best possible
sound out of your mixes. Compression is used as an automatic
volume control, and is usually used to reduce runaway transients
with too much amplitude for their own good. However, there are
several more interesting ways to use compression as well (Phil
Moffa has an awesome post on using compression in “side-
chaining”, and electronic musician has a great post on using
compression creatively). There are several things that all
compressors use to function: Threshold- The threshold is the
chosen dB level after which all gain will be reduced Ratio- The
ratio is how “harsh” the compression will be. 2:1 is mild
compression, 20:1 is severe and moving into limiter territory.
Knee- At the threshold, how linear vs. curved the compression
will be is called the knee (think of the bending of a knee!).
Attack/Release- How quickly the compression happens and ends.
Compression takes time to master, and it takes listening to lots
of mixes before you can get a hand