Compression for balance

One of the most common uses of a compressor is simply to balance out the level of a signal and make its dynamic range more consistent. This is useful because, if a signal’s dynamic range is too great, it can be difficult to set the fader to one position for the whole song. Take for example a vocalist who performs a take with varying dynamics. If you set the fader to the correct spot for the quiet parts of the performance, then the vocals will be too loud during the louder parts. If you set the fader for the louder parts, then the vocals will be too quiet during the quieter parts. This is true of any instrument that exhibits a fair amount of dynamic range.

You can approach the balancing of levels using compression in different ways. You could set the compressor’s threshold so that compression is only applied to the signal’s loudest parts. You could use this method to attenuate only the loudest parts of a vocal or to turn down a loud snare drum in the overhead recording of a drum kit, whilst leaving the rest of the signal uncompressed.

Alternatively, you could set the threshold lower so that more of the signal is compressed. This is a great approach for reducing the overall dynamic range of a track and achieving more balanced levels. Keep in mind also that applying a smaller amount of compression using a lower ratio, to more of the signal using a lower threshold, can often be more transparent than applying a larger amount of compression using a higher ratio, to a smaller portion of the signal using a higher threshold.

When balancing signals, fast attack and release times are generally preferred. This ensures that the compressor reacts quickly to level changes to keep the signal balanced.