Knowing how a compressor works is important for achieving professional-quality sounds. Compression is a powerful tool that helps control the dynamic range of audio, enhancing clarity, balance, and impact. In this guide, we will dive into the basics of compressing.

What is a compression?

Compression is an extremely useful way to reduce the dynamic range of audio signals. It makes the loudest parts of the sound closer to the quieter parts, creating a more balanced and controlled performance. Compression really helps to improve overall mix in many ways, for example by taming uncontrolled peaks and boosting low-level details.

Key Parameters

In this picture we have defined the key parameters of compressors:

What to use it for? 

1. Dynamic Range Control

-Using a compression to even out the dynamic range, bringing loudest and softest parts closer to each other

Threshold → set this to determine at what level the compression starts to take effect

Ratio → this controls the amount of control applied

Attack & Release → These shape how quickly the compression responds to changes in signal

2. Glueing Mix Elements

-A gentle compression to help to glue all elements in the mix together 

Ratio → Use a low ratio (1.5:1-3:1) 

Threshold → Use it gently to smooth out the dynamics

Attack & Release → Try slower attack time to let transients pass through (while compressing overall mix) 

3. Adding Sustain to Instruments 

-Add a sustain and presence to instruments in your mix, for example guitars and drums

Ratio → Add a moderate ratio (4:1-8:1) to control the dynamics

Attack & Release → Listen which attack and release times lets instruments sound as natural as possible

4. Controlling Bass Levels

-Add this to bass instruments or tracks to control the levels and make them sound more consistent

Ratio → Use low ratio (2:1-4:1) 

Attack & Release → Allow the initial transients of the bass to pass through unaffected

5. Parallel Compression (New York Compression)

-Use this to maintain the dynamics of the original track while adding extra punch and presence 

1. Many compressors have wet/dry knobs in them. Try adjusting this, first for example to 50% and listen which sounds the best for your track.
2. Another option is to send your track to auxiliary channel. Add to that aux -channel heavy compression with high ratio (10:1 or higher) and fast attack and release times. After that, blend the compressed signal with the original track to get the desired balance.

6. De-essing 

-With de-essing you are able to reduce sibilance and hardness in “sss”-sounds in vocal tracks

-Set the sidechain input to bandpass-filter that emphasizes the sibilant frequencies 

Threshold & Ratio → Try to get effective reduction without affecting the rest of the vocal

7. Drum Compression

-Apply compression to each drum track or to the drum bus to shape the sound of the drums

Ratio → Use moderate ratio (3:1-6:1) 

Attack & Release → Adjust these to enhance or tame the transients

Of course, there are many ways to use compression in music production projects, including the ones listed above. Compressor can also be applied to the master bus or subgroups to unify the elements of the mix, which helps control inconsistencies and will make the mix sound more professional. For any producer or engineer, it is important to understand the basics of compressing sound. Remember to experiment with different settings with ratio, threshold, release, attack and makeup gain. With time it will become an indispensable tool in your music production arsenal.