Dynamic Processors Techniques
Virtually all modern day pop, dance and rock songs have some form of compression on them. There a variety of different uses for compression, with the primary ones listed in this article.
Not sure what a dynamic processor is? Learn the fundamentals about dynamic processors.
Compressing Individual Sounds
It is near impossible for vocalists to sing at a constant volume. They may sing quietly on some parts and way too loud on others. A compressor can reduce the dynamic range of the vocalist to a more manageable level allowing every word to be heard at a constant volume. However, be aware that the vocal should never be over-compressed as this can lead to it sounding restrained and unnatural.
To compress the vocal, start with a relatively fast attack of about 20ms and a moderate release time of about 300ms. If the compressor has an option to choose soft or hard knee, pick soft knee for a more musical sound. The ratio should be set quite high to start with; usually about 8:1. Whilst the vocalist is singing relatively softly, slowly turn down the threshold from its maximum position until there is the slightest change in volume reduction (usually about -8dB). Boost the output control until the quiet part is at a good level or stick on auto gain compensate. Now find a part in the song where the vocalist is singing loud. Slowly bring the ratio control down until the sound seems less ‘squeezed’ but still constant. The ratio should probably be set at about 4:1 when finished.
The kick and Snare drum
The dynamics of a kick drum can vary quite dramatically as the drummer will hit them at various strengths. Compression makes the drum sound more constant and punchy.
To compress a kick drum or snare, start with a high ratio of about 8:1. Position the attack at about 5-10ms and the release at 340ms. Bring the threshold control down until a constant thumping sound is achieved. Switch on auto gain compensate.
Bass guitars are hard to play at a constant volume. Applying compression helps to ensure that the bass doesn’t keep wandering in and out of the mix.
To compress a bass guitar, start with a high ratio of about 6:1. Position the attack at about 5ms and the release at 100ms. Bring the threshold control down until a constant thumping sound is achieved. Switch on auto gain.
To Prevent Distortion
Often a heavy kick drum or loud bass guitar will cause large peaks in the signal that cause distortion. The problem can be solved using a limiter.
To limit a sound to prevent distortion, position the attack and release controls at their fastest so they respond immediately and recover immediately. If there is an option to choose soft or hard knee, pick hard knee so the limiter kicks in abruptly. The ratio should be 20:1 + for maximum compression. Adjust the threshold at the point where the music volume just starts to decrease, then back it off slightly.The compressor will now act as a brick wall to any sound that meets the threshold.
Adding Punch to a Sound
Compressors are often used to add punch to a sound. This is useful if there is a rhythmic pattern that somehow lacks definition in the mix. The trick is to set the attack to just let the sound through and set the release to extend the sound. A perfect balance has to be met when using this trick as a too fast an attack will reduce punch where as a too slow release will make the compressor pump out of time. If done correctly it is possible to generate some pumping peaks.
To achieve a pumping rhythmic sound, start with a slow attack of about 80ms and a moderate release time of about 400ms. The ratio should be set high at about 20:1. Slowly bring the threshold down until a pumping sound is audible. Switch on the hard knee option if available.Producing a good pumping sound can be hard to achieve. Spend time adjusting the attack and release times until the perfect sound is met.