When I first started working in the audio industry, compression was one of the hardest things for me to wrap my head around. Not only did I not quite understand what it did and what it was used for, but I also didn’t know what each parameter did or how to adjust them to get the sound I wanted. It felt like twisting random knobs and hoping for the best. However, over time, I realized compression isn’t as intimidating as it seems—it’s just about controlling dynamics and shaping sound in a musical way.
In this post, I want to explain how to use a compressor and why it’s such a powerful tool.
So, what is compression?
At its core, compression is a tool used to control the volume of audio signals; it helps even out loud parts, making the overall sound smoother and more polished. But to understand compression, it’s essential to break it down into its key components: threshold, ratio, attack, release, and makeup gain.
Threshold: The threshold determines the level at which the compressor starts working. If the input signal exceeds the set threshold (e.g. -10 dB), the compressor will begin to reduce its volume. Signals below this threshold will remain unaffected.
Ratio: The ratio works hand-in-hand with the threshold. While the threshold determines when the compressor starts working, the ratio dictates how much the signal is reduced once it crosses the threshold. This parameter is expressed as a ratio (e.g., 4:1), where the first number represents the input signal level above the threshold, and the second number represents the resulting output level. For instance, with a 3:1 ratio, if the input exceeds the threshold by 3 dB, the output will only increase by 1 dB.
Attack & Release: Like the threshold and ratio, the attack and release work hand in hand. The attack controls how quickly the compressor responds once the signal crosses the threshold. A fast attack clamps down on the signal almost immediately. In contrast, a slower attack allows the initial transients to pass through before compression kicks in. The release, on the other hand, determines how quickly the compressor stops compressing after the signal falls back below the threshold. Together, these settings shape the natural flow of the sound, from tight and controlled to smooth and transparent.
Summary
Compression might initially seem complicated, but once you understand its key parameters—threshold, ratio, attack, and release—it becomes an incredibly powerful tool in shaping your sound. Whether you’re tightening up vocals, adding punch to drums, or smoothing out a mix, a good understanding of compression allows for more professional and polished results. Don’t be afraid to experiment and trust your ears—it’s the best way to truly master this essential audio skill.
About the Author
Rhyon Cook is a dedicated music producer passionate about turning creative ideas into polished productions. With hands-on experience and a focus on constant learning, Rhyon enjoys breaking down complex audio concepts to help others on their own music-making journey.