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The Many Types of Compressor - When to Use Each as a Workhorse or a Wildcard Plugin

Jul 30, 2024

“Just a compressor” often isn’t good enough any more. The tools of music production have evolved to cover a range of niches and use cases. Today’s toolkit includes everything from multiband compressors that treat different frequency ranges independently to signal smoothers built to enhance a certain type of sound.

The Many Types of Compressor - When to Use Each as a Workhorse or a Wildcard Plugin

But there’s still room for creativity with this highly specific toolkit. In this article, we’ll outline nine of today’s compression and dynamics device types, and explain how each one ‘should’ be used. But then, for each one we’ll also go further and suggest a wildcard use: a creative way to use it that isn’t

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Compressor: The Original Dynamics Controller

A compressor is the time-honored device for getting a handle on dynamics. A compressor – such as our own Renaissance Compressor (“R-Comp”) – is capable of controlling transients using quick attack and release times or painting with a broader brush by moving slower to add character and power to a signal.

R-comp at work within a DAW project

There are two general ways to use a compressor: one is to gain control over a signal to keep it ‘held down’ in a mix; the other is to sculpt and change the character of a sound, bringing out more of its body and sustain for example.

Using mid-side Compression: A Wildcard Use Case

A wildcard use for a compressor is to reduce only the transients within a stereo track. Using StudioVerse AudioEffects.

Make any plugin mid-side in StudioVerse

Load two Parallel Split racks. Set one rack to Sides, the other to Mid. Strap RComp within the Sides rack and set this up with a fast attack time and let it work its magic only on the sides (aka stereo) portion of say the stereo field of a drum track or percussion track. Reducing transients all around the sound stage is a great way to bring your mono (mid) energy closer into focus, removing distractions.

Sidechain Compressor: In Its Own Category

That’s right, a compressor fed by an external sidechain input is still a bog-standard compressor, but the operation and usage is so different that we’re classing it as its own type of compression processor for the purposes of this article.

Waves C1 Compressor removing transients from a signal

A sidechain compressor operates in a sort of ‘upside down’ way. Whether you’re quickly ducking a sound against another when Mixing Kick and Bass to Perfection, or making a pumping, breathing pad sound, the mission is to cut out, not to control and reduce.

Using Sidechain Compression: A Wildcard Use Case

Create a rising reverb effect on a track, giving a surreal and otherworldly quality to sounds. Follow the steps below to get this setup:

  1. Locate the track you wish to apply dynamic effects to (such as a lead vocal or guitar channel).
  2. Insert an empty mono bus on this track. (Set the level of this bus to unity and enable pre-fade.)
  3. For good housekeeping, name this bus "Dynamic Effect."
  4. Set up an effects return with a reverb or delay plugin:
    • Create a stereo auxiliary track
    • Insert a reverb or delay plugin
    • Set the input of this channel to an available stereo bus; and
    • Insert this bus within your vocal or guitar track's send's section
  5. Insert a compressor that provides a sidechain input on the effects return auxiliary after the reverb or delay plugin.
  6. Assign the sidechain input within this compressor to the "Dynamic Effect" bus.
  7. Increase the level of the bus sent to the effects return on your vocal or guitar track.
  8. On the compressor, set threshold, ratio, attack and release controls to taste.

Multiband Compressor: Surgicomp

The multiband compressor was a sensible idea: instead of setting up compression on a wideband signal, split that signal into (usually four) component frequency ranges, and use a separate compressor on each, with different settings. A great example is our own C6 Multiband Compressor.

Waves C6 Compressor at work in a project

Typically, a multiband compressor is a go-to tool of the mastering engineer, with its ability to control dynamics where needed but leave them alone where not. In mastering, Listening for Details is Crucial, and finding the right tonal balance is very necessary, and the multiband compressor solves both.

Wildcard Multiband Compression: Getting Perfect Bass Tones

Take a bass sound with energy that goes up to the mid frequencies. Use a band to control the instrument’s sub bass frequency area, making sure not to set the Attack too short. Optionally, set a band for the ‘bass’ (as opposed to sub bass) frequencies too. Finally, use one more band to compress the rest of the frequency range separately. This gives you control over your complex bass sound’s power and weight (bass) and its ability to cut through the mix (mids).

Limiter: More Than Just a Brick Wall

A Limiter prevents an audio signal from going beyond a certain point. In practice, a limiter can usually be described as a compressor with a very high Ratio. An example of a great plugin limiter would be our own L3 Ultramaximizer. So how is a limiter’s usage different from a standard compressor? Often it’s context.

Waves L3 Ultramaximizer in Ableton Live

A limiter is usually used as a mastering processor, and its point is to remove any stray peaks ready for the final output of the entire mix. A different engineer and a different genre may call for a lower Threshold to be used, bringing about more peak reduction, but this can introduce distortion. An ideal limiter will have been designed to keep distortion to a minimum, and when comparing different limiters at the same settings, it’s often possible to hear the difference.

In the video below you, hear the difference in character between L1, L2 and L3.

Here’s Another Way to Use a Limiter

Even though a limiter aims to give little distortion, when pushed hard it will deliver just that. Drive a limiter like it’s rented, and the distortion it gives out has a harsh character that can sound absolutely beautiful on electric piano sounds, giving them bite and heat that a distortion alone won’t manage.

Clipper: How is it Different?

A clipper acts in a similar way to a limiter: it scalps off the top of any audio that dares cross its threshold.

The difference between this and a limiter is that the clipper doesn’t aim to reduce distortion, usually missing Attack and Release settings and dispensing with any nuance in the algorithm that determines how gain reduction is applied and by how much.

How to Use a Clipper Irresponsibly

Not that a clipper is ever really seen as a nuanced or even delicate effect to add to a mix, but its use is often applied to only the ‘tips’ of each waveform peak. Using a clipper set intentionally low will introduce distortion, in the exact way a waveshaping distortion device will. Try using a clipper on a parallel track alongside a vocal, blending in the trashed-up version of the sound as needed through your track.

Transient Shaper: Goes Beyond Drums

With their signature dual-knob design – one for leveling transients and the other for leveling a sound’s body or ‘sustain’ – transient shapers are very much set up to do things in a certain way. Plugins like Smack Attack can go beyond with a few extra controls, but the core concept remains.

Waves Smack Attack is a transient shaping plugin

This ‘core concept’ often means adding a transient shaper to a drum channel – could be a snare, a kick, an entire drum buss or anything else – and sculpting its bite and body to fit in with other elements of a mix.

A Wildcard Transient Shaper Tactic

An underappreciated use of the transient shaper is on guitar. Whether acoustic or electric, the guitar’s signal can easily benefit from the two-stage controls of the plugin, especially given its highly dynamic nature straight into a recording input. Too spiky and transient? Not enough body? This is a great solution to get the guitar cooking.

Dynamic EQ: Modern Compression

A cross between EQ and compression, and a cousin just like multiband compression, only on the other side of the family, dynamic EQ – like our own F6 plugin – takes a regular old band of EQ – a bell or a shelf – and makes its gain respond to the signal flowing through the band in the same way a compressor would.

Waves F6 Dynamic EQ at work inside a DAW

Dynamic EQ works well precisely because of its threshold of operation. If the band doesn’t have much signal flowing through it, you get no reduction. Only when the band is pushed hard does the compression kick in, and the result is a control over that frequency band. Dynamic EQ can be used to reduce harshness or as a more natural-sounding method of EQ. There’s more it can do too though…

Dynamic EQ in its Wildcard Use Case

How about sidechaining a dynamic EQ band? Just like sidechaining a compressor, this can create ducking only when a competing element pops up. When sidechaining kick and bass, using a dynamic EQ shelf instead of a full-band compressor means you can duck just the low frequencies of a bass whenever a kick plays, rather than the whole frequency spectrum, which would be more noticeable.

Smoother: New Comp on the Block

A spectral version of compression processing, a smoother almost acts like a multiband compressor with many more than the usual four or six bands. With so many frequency bands, you can’t set up controls for each and every one, so a plugin like Silk Vocal will contain some intelligent ways of managing its per-band processing while giving you easy-to-understand controls.

Waves Silk Vocal is a frequency soothing plugin

Using Silk Vocal in Unintended Ways

Our vocal-smoothing plugin has some other cool uses you can try out. How about using it on a reverb signal? A reverb is meant to be a smeared bed of sound, and so a smoothing plugin like Silk Vocal can create the effect in a slightly different way, giving you a highly balanced but tonally ambiguous reverb response to fit into the mix.

De-esser: Also a Compressor!

Finally, we shouldn’t forget this classic tool. The de-esser was originally envisioned as a “frequency-conscious compressor” that would compress the full signal when a tight band of sibilant frequencies breached a threshold. But revisions over the years – including our own DeEsser – have turned de-essers into more tailored, sibilance-seeking surgical instruments.

Waves DeEsser loaded within a DAw project

A Less Obvious Use for a De-Esser

Try a de-esser out on a drum buss in your next mix. It can tame harsh sounds from overheads, with cymbals being a particular example. Going further, though, a good de-esser should also tame harshness wherever it crops up in the high frequencies, including from individual drums.

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