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Learn how to use an audio compressor step by step, with a real-world example on kick drum.
If you’ve ever searched for how to use an audio compressor, chances are you’ve found vague advice or overly technical explanations. In this article, we aim to demystify audio compression by showing you how to set a compressor step by step, using a kick drum as our test subject.
We’ll cover the essential theory and apply it in practice using the HoRNet Multicomp Plus MK2, a versatile and transparent plugin that offers full manual control. Whether you’re a beginner or someone who’s been turning knobs without fully understanding them, this guide is designed to help you grasp both how and why to use compression.
An audio compressor is a tool designed to control the dynamic range of a sound. In simple terms, it reduces the difference between the loudest and quietest parts of an audio signal. When a signal crosses a certain volume threshold, the compressor reduces its level by a defined amount. This helps to:
Control peaks that jump out of the mix
Make sounds more consistent
Increase perceived loudness without distortion
Add punch and energy
Compressors are widely used on vocals, drums, bass, guitars, synths, and even entire mix busses.
Before we jump into practical application, let’s quickly define the five main controls on a typical compressor:
Threshold – The level at which the compressor starts to work. Signals below this are untouched.
Ratio – Determines how much the signal is reduced once it exceeds the threshold. A ratio of 2:1 means that for every 2 dB over the threshold, only 1 dB comes out.
Attack – How quickly the compressor responds after the threshold is exceeded.
Release – How quickly the compressor stops compressing after the signal falls below the threshold.
Makeup Gain – Used to compensate for the volume lost during compression.
Using a compressor is not just about controlling levels—it’s about shaping the feel of a track. A well-compressed kick drum, for instance, sounds punchier, tighter, and more controlled. In a busy mix, that difference can be huge. But compression done poorly can kill dynamics, cause pumping, or make things sound unnatural.
Let’s go through the method we demonstrated in our video tutorial, using a synthetic kick drum sample and the HoRNet Multicomp Plus MK2 in VCA mode—a very neutral and predictable compression type.
Start by turning the ratio all the way up, and setting both attack and release to their minimum values. This will make the effect very obvious. Then, lower the threshold until you see a strong amount of gain reduction (e.g., -18 dB). This helps you hear clearly how compression affects the sound.
At this point, the kick will likely lose a lot of its body and sound very “flat.” That’s okay—it’s part of the learning process.
Now, slowly increase the attack time. This lets some of the transient (the initial “click” or “punch”) of the kick come through before compression kicks in. Listen carefully—when the sound starts to regain punch and energy without sounding out of control, you’re in the right spot.
Next, raise the threshold slightly until your gain reduction meter shows around 6 dB of reduction. For consistent sources like samples, this is a good general target—it reduces dynamics without over-processing. On live or more dynamic sources like vocals, you might go for 8–10 dB instead.
With threshold and attack set, reduce the ratio to something more musical—maybe around 3:1 or 4:1. This gives you a more natural compression feel, while still controlling peaks effectively.
Adjust the release so the gain reduction meter returns to zero just before the next kick hits. If it releases too quickly, you risk introducing intermodulation distortion or audible pumping. If it’s too slow, you lose groove and punch. Aim for a smooth recovery that keeps the rhythm intact.
Finally, raise the makeup gain so the compressed signal matches (or slightly exceeds) the original loudness. The compressed kick should now feel tighter, punchier, and more present in the mix.
Many plugins today offer “auto” features—automatic threshold, attack, release, or makeup gain. While these are helpful time-savers, they work best if you already understand what the compressor is doing. Knowing how to use a compressor manually gives you creative control and allows you to make better decisions—even when using automatic tools.
At HoRNet, we’ve built auto features into several of our plugins—including H76, H160, H4K, and of course Multicomp Plus MK2—with algorithms based on the method we’ve just described. These features help you work faster, but they rely on a solid foundation of audio knowledge.
Learning how to use an audio compressor is a crucial step for any producer or mix engineer. By understanding what each control does and hearing how changes affect your sound, you’ll gain the confidence to use compression as both a technical tool and a creative one.
Start with theory, test it on something simple like a kick drum, and trust your ears. The more you experiment, the more natural it becomes.
