Advanced compressor techniques

If you understand Compressor Basics, it is time for some more advanced use of the compressor technology. As mentioned above, the compressor normally monitors the main input signal through a side-chain circuit, but we could send another signal to the level detector. The most common example would be the radio DJ. While music is playing, speaking into the microphone will cause the level of the music to drop so that it's easier to hear the DJ talking. To do this we have to insert the compressor on the music track but send the vocal to the level detector.

This technique is called "ducking". When mixing in the studio, ducking can also be used to emphasize certain elements, such as the kick drum. The kick could lower other tracks in the mix, increasing its "presence".

FabFilter Pro-C also provides the option to patch an EQ unit before the level detector to make the compressor respond only to frequencies passed on by the EQ. Remember that this EQ does not effect the actual input signal but only the level detector. The gain control then adjusts the actual input signal.
"Why?" I hear you ask... Maybe we want the compressor to ignore the low end of a drum mix when compressing that drum mix. Then we need a high-pass filter before the level detector so the level of the low kick drum will not cause the compressor to react.

If you have more questions you could start reading this article (the Internet has many good articles about this subject).

Just one more thing we'd like to add. When using compression there is only one thing to remember: there is no rule. Experiment with settings and all the possibilities FabFilter Pro-C has to offer!

Next: Mid/Side introduction