I feel that I didn’t thoroughly explain what a compressor does and why you should use a compressor in my video above; therefore, I will further elucidate in this post. A compressor allows you to make the loud quieter and the quiet louder. For example, say you have a vocal recording of a singer and the singer was not the most talented singer you ever worked with. She would sing softly and abruptly sing louder. To help fix this issue, you can employ a compressor to make the soft parts louder and the louder parts quieter. In reality, you will probably have to ask her to go home and practice or just find another singer. You should always try to get the best recording of something first and then start fixing minor issues afterwards. Compression does help but it is not a silver bullet.
Why should you use a compressor? You should always listen to you recording first and identify what needs to be done. Do not just throw on a compressor to one of your tracks just because. You need to know why a compressor is necessary in the first place. This applies to other things as well such as, EQing, reverb or anything that you do to your tracks. A reason why you should use a compressor is when you want to create a certain effect or sound. For instance, creating that Dubstep kick sound will require a compressor. Another reason to use a compressor would be the predicament I mentioned earlier with the singer singing loudly and softly.