Using Compression

Though you can say that using a Compressor in general is about reducing the dynamic content of a signal thereby having better control, there are many different angles on how to use compression. Depending on the specific application you may have different starting points and goals when you apply compression. As personal style also is a major consideration it is hard to give specific answers on how to use compression. However, here are some guide- lines.

First a short description of the basic parameters.

Illustration

Dynamic Section

Threshold

When the signal rises above the set Threshold point the Compressor is activated.

Ratio

The Ratio setting determines how hard the signal is compressed.

Attack

The Attack time is the response time of the Compressor. The shorter Attack time the sooner the Compressor will start to work after the signal rises above the set Threshold.

Release

The Release time is the time it takes for the Compressor to release the gain reduction of the signal after the signal drops below the Threshold point again.

Example:

Threshold is set to -6dB

Ratio is set to 2:1

Attack is set to 10ms

Release is set to 300ms

A relatively loud musical phrase reaches -2dB on the Input. As the Threshold is set to -6dB, 4dB of the signal will be processed. The Ratio of 2:1 means that each of the 4dBs above Threshold will be reduced to 0.5dB. So, the 4dB above Threshold on the Input side will be reduced to only 2dB on the Output. This gain-reduction is reached in 10ms which is specified by the Attack time. When the Input signal drops below the Threshold (-6dB) again, the Compressor ceases to process/reduce the Output signal. The Release time specifies how long it will take until no processing is taking place.

Spectral Adjust Section

Selecting Full-range or Multi-band mode

Evaluate the frequency range of the source material. If your source material has a wide frequency range with peaks in specific frequency areas, the Multi-band mode should probably be your choice. If on the other hand you are working on e.g a repeating back-up vocal harmony within a relatively small frequency area the Full range mode would apply perfectly.

Better Definition of Vocal material

If the object is to define the Source material e.g a voice a gentle compression would be appropriate. By delicately controlling the peaks of the signal you are able increase the overall level of the signal and the low level content of the signal will be increased. Try using a high Threshold setting to keep the dynamic content of the signal and to avoid processing the entire signal all the time. A low to medium Ratio and Attack setting will give you the soft and often desired compression used when working with vocals.

Guideline Settings

Ratio: 2:1

Attack: 10ms

Release: 200ms