Buss compression is certainly not a new concept, however, it is an effective and reliable engineering tool and its basic principles are vital considering you are affecting multiple voices.
When approaching buss compression, there are two essential tools at your fingertips: Attack and Release – these two tools, when properly utilized, will have the ultimate say in the outcome of your efforts.
The attack and release functions of a compressor will tell its detector how to react to signal that passes through. An effective use of attack and release will essentially allow you to make conscious envelope changes to the signal rising above the threshold at the detector. This brings about the main philosophical concept behind compression, which is to shape the signal, rather than merely restrict its dynamic range (dynamic restriction is part of shaping the signal, not the end purpose). The attack and release controls are what really provide the push and pull effects of compression.
With this in mind, I have provided examples of effective and ineffective buss compression, focusing on attack and release settings, for a few simple approaches.
All of the following audio passed through the same compressor with the same settings (beside attack and release) and a ratio of 1.5:1 with an average gain reduction of 4 dB.