Compression, More than meets the Eye.

Most people think of compression as a process which makes loud parts softer and soft parts louder. That, in basic terms is true but there is much more to using compression than dynamic processing and further, why do people spend thousands of dollars on a specific compressor when they all just do the same thing?

Read on and you will find out why.

Im going to show you a simple sine wave form using test generator, you can do this yourself using your DAW.

Looks pretty standard.. Now take a look at that same wave form with an 1176 plugin doing what it does.

One thing is very noticeable, the addition of 2nd and third order harmonics to the original signal.

You see compression isn't just the process by which the signal is dynamically altered. It's the addition of artefacts in combination with that dynamic process which gives great compressors there reputation.

So as the fundamental is reduced and the compressor works harder, more and more harmonics are added, giving that signal not only an added eveness to the dynamic range but also a perceived loudness and audibility that wasn't there before. Isn't that something!

To further the point take a look at a standard digital compressor which hasn't been modelled after specific analogue unit but just designed to do the dynamic processing:

You can see the compressor is being hit quite hard but no additional harmonics have been added. This is the difference between a strictly digital process and the analogue world. Its quite something isn't it.

Neither is right or wrong but it's horses for courses. If you want your sound absolutely unchanged then a digital process will do that for you. But of you want all those lovely artefacts and harmonics then you have to step into the analogue realm.

Finally take a look at the CLA 2A at work:

Being an opto/ tube compressor it adds even more of those harmonics to the signal an probably why it works so well on bass and vocals where a lot of colour is required.

So next time you reach for a compressor have a think not only about the strict functionality but the tonal colour in combination with that dynamic process that makes compression an amazing thing!

Enjoy.