How a Compressor Works

The compressor is a confusing device that is often overused or not used enough. Its main function is to control an audio signal by making the loud sounds softer and the soft sounds louder. By doing this, it bring gives you control of the signal overall. If overused it can sound too flat or not realistic. It would start to affect the natural emotions and volume changes of a signal. If not used at all sometimes can cause your mix to sound to natural. Form some genres of music that is a good thing like jazz, orchestral, and folk. For other genres that might not be what your looking for. Pop, Hip-hop, Newer Rock, and most R&B heavily compress.

Device parameters

1. Threshold
this is the point where you want to start compressing. You would put it on a curtain db level that you think would be good to control you mix without overdoing it. This may vary from different genres as well. For instance if you have a waveform that is mostly constant at level (A) and every once in a while you would get a burst of signal about 6dB than you would need to set you threshold somewhere a little higher than level (A).

2. Ratio
this is pretty clear in its name. on the device itself it might read a ratio of 3:1. This says that for ever 3dB past the threshold, the compressor will compress the signal down to 1dB. You can adjust the ratio to extreme compression witch is about 7:1 all the way past 30:1,35:1 up to infinite. When it is set to infinite, this is an limiter. A limiter doesn't allow any signal to pass the threshold.

3. Gain
when you compress a signal you will have a steady dB level. When this happens you will need to raise the signals volume to tape. This is the same as moving a fader's volume level up but this is the output of the device itself.

4. Knee
the knee can be adjusted form soft to hard depending on the amount of control you need. A soft knee can smooth the compression out but may allow some of the instant burst to become uneven or unnatural.

Misuses
It is obvious when you misuse a compressor. Too much compression can lead to a flat base of a sound. After all, the point of a compressor is to control the dynamic range of a signal. Most of the time dynamic rage makes of breaks a mix.