RR 30 Dynamics

This section is all about dynamics. The dynamics of an audio signal is about the range in level of the signal: from the softest whisper to the loudest explosion. You can control the level by simply riding a fader on a mixer, or by f.e. using a compressor.

This section is about using the MComp in ways different then simply using it as an insert effect. We'll start with an effects patch without CV signals and continue including these. All patches in this section are designed as insert effects.

To refresh your memory I'll start with a short explanation of a compressor.

A compressor is a device that controls the level of an audio signal. As long as the level stays below the Threshold the compressor doesn't alter the sound. When the level does rise above the Threshold the compressor will start working. It then reduces the level of the audio signal. The reduction is controlled by the Ratio. A Ratio of 4:1 means the level will be reduced by a factor of 4. So if the input level rises 8dB above the Threshold, the output level will be only 8 /4 = 2dB above the Threshold. The Attack controls how soon the reduction will occur when the level is louder then the Threshold. The Release controls how long it takes for the compressor to stop reducing the level after the input signal falls below the Threshold.

A compressor with sidechain has an extra input. The compressor reacts to this sidechain input, but applies compression to the normal input. Therefore the compressor only starts reducing the level of the normal input if the level of sidechain input is louder then the Threshold. When the level of an announcer is greater then the Threshold the compressor will reduce the level of the background music on the airport.

A classic de-esser patch works by splitting a vocal track both into the normal input of the compressor and into the sidechain input. The Threshold is set so the compressor doesn't work. Now the sidechain split is equalized to enhance the frequencies you want to reduce in level, the sss-sounds are enhanced. This way the level of the sidechain will be louder then the Threshold whenever these enhanced frequencies, the ssss-sounds, are present. Therefore the compressor will only reduce the level of the normal input when the enhanced frequencies occur. To make sure the compressor doesn't work when other frequencies are strongly present, the low frequencies of the sidechain input can be attenuated.

To correctly tune the equalizer the compressor has a sidechain pre-listen switch, or on the MComp a sidechain solo button. When activated it allows you to listen to the sidechain input so you easily find the correct frequencies to enhance.