The Ultimate Audio Compressor Buyer’s Guide 2021


So you’re wondering which dynamic range compressor you should buy, rent or otherwise try out. In this comprehensive buyer’s guide, we’ll go through everything worth considering before you make any decisions about a compressor.

If you’ve found yourself asking, “which compressor should I buy?” this extensive resource is for you.

Please feel free to jump around this article and read all additional resources I have provided links to.

With that, let’s get into this comprehensive audio compressor buyer’s guide to help you in your next compressor purchase!

Related article:
Top 11 Best Audio Compressor Brands In The World


Table Of Contents


What Is Your Audio Compressor Budget?

The first thing to consider when making any purchase is your budget. Money can be a touchy subject for some, and so I’ll keep this section brief.

I would never advise anyone to overspend on any audio equipment. Know what you can realistically afford, and do your best to stay within those limitations, whatever they may be.

Compressors, like many audio devices, range significantly in price. The market is rather large, and so there should be a good selection for any budget.

Note that some retailers offer payment plans, which could be an option.

Consider the cost to benefit ratio of the purchase of the compressor. For example, if the compressor is needed for business, perhaps stretching the budget is more appropriate. On the other hand, if you don’t plan on making money with the compressor, perhaps a more conservative budget is appropriate.

Also, consider any additional accessories or upkeep that may be required for your dynamic range compressor.

Only you can determine your budget. All I’m here to say is that you should consider it.

Back to the Table Of Contents.


Compressors Vs. Limiters

Before getting too far into this article, let’s quickly discuss the differences between compressors and limiters.

Though both processes act to reduce the dynamic range of an audio signal/track, modern-day compression and limiting aren’t exactly the same.

Compression is the process of reducing signal levels above a set threshold by a defined ratio. It is according to the ratio that the level is reduced above the threshold. For example, a 4:1 compressor ratio means that for every 4 dB, the signal goes above the threshold at the input, the output signal level is only 1 dB above the threshold.

Limiters originally came about as compressors with high ratios (20:1, for example). The original limiter units acted to clamp down hard on the signal, making it impractical to have an output much higher than the threshold (imagine having to go 20 dB above the threshold to get +1 dB at the output, and how squashed the resulting audio would sound).

Because limiters effectively limited the output level to just above the threshold, they became useful for keeping signal levels safe and preventing overload in audio equipment in recording studios, broadcast studios, and other audio applications.

Modern limiters are often designed with ∞:1 ratios, which means they stop the signal from surpassing the defined threshold (assuming fast enough attack times). These limiters are regularly used in digital audio settings to ensure the signal levels never surpass 0 dBFS, which would lead to digital clipping.

So, if we see the term “limiter” or “limiting amplifier,” know that it could be a hard limiter (in the modern sense) or act more like a compressor with a very high ratio (in the original sense).

Related My New Microphone article:
What Is The Difference Between Audio Compression & Limiting?

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Audio Compressor Hardware Vs. Plugins

When choosing a compressor, it’s definitely worth weighing the option of a hardware compressor and a compressor plugin.

Audio plugin technology has come a long way. With the prevalence of digital audio and digital audio workstations (DAWs), plugin compressors can be much more practical than their hardware counterparts.

Compressor plugins can be original designs, and digital processing and programming have made some of these compressor designs much more powerful and versatile than any hardware design. In addition to new, exploratory ideas, there are also plenty of plugins on the market that emulate classic hardware designs and performance (right down to the graphic user interface).

One compressor plugin can be inserted on as many audio track inserts as your DAW and CPU can handle, unlike hardware compressor units, which can’t be duplicated.

Furthermore, plugins require little upkeep (perhaps an update once in a while) and no physical maintenance. The best part; they are much more affordable than hardware.

That all being said, having a hardware compressor in your setup is nice. There’s something about running audio signals through physical circuits that is both pleasing to the touch and the ear. If you can afford it, I’d recommend looking into a physical hardware compressor.

Related My New Microphone article:
Top 11 Best Audio Plugin (VST/AU/AAX) Brands In The World

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Audio Compressor Form Factors

Hardware compressors come in a variety of shapes and sizes. Let’s consider the following commonplace compressor form factors:

Rackmount Compressors

Rackmount compressors fit into the standard 19″ racks, which are commonly found in recording studios, broadcast studios, and live sound systems.

Related My New Microphone articles:
Top 11 Best Audio Studio Equipment Rack Brands On The Market
Top 11 Best Rackmount Case Brands On The Market

Tabletop Compressors

Tabletop compressors come in a variety of shapes and sizes but are all designed to sit on a flat surface rather than to fit into a rack/modular system.

500 Series Compressors

500 Series compressors fit into modular 500 Series chassis. This modular format is common in studios and is a popular choice for mobile recording rigs due to its ease of transportation. The chassis typically provides power and often provides the inputs, outputs and internal routing for its modules.

Related My New Microphone articles:
What Is 500 Series Audio Equipment & Is It Worth It?
Top 11 Best Audio Brands For 500 Series Modules/Equipment

Modular Synth Compressors

Though not as common as the other form factors, you may come across compressors designed for modular synth formats such as 5U (Moog) or Eurorack.

Related My New Microphone articles:
Top 11 Best Eurorack Module Synth Brands In The World
Top 11 Best MU (Moog-Unit) Synth Module Brands In The World

Modular Console Compressors

Studio/recording, broadcast and live mixing consoles can also be modular. There is a small market for modular compressor units for high-end modular consoles.

Related My New Microphone articles:
Top 11 Best Mixing Board/Console Brands For Home Studios
Top 10 Best Studio Recording/Mixing Console Brands

Top 10 Best Live Sound Mixing Board/Console Brands

Effect Pedal Compressors

Compressor and sustainer pedals are relatively common for bassists and guitarists. You’ll often find compressors pedals on pedalboards.

Related My New Microphone articles:
What Are Compressor Pedals (Guitar/Bass) & How Do They Work?
Top 11 Best Compressor Pedals For Guitar & Bass
Top 11 Best Guitar/Bass Effects Pedal Brands To Know & Use
Top 11 Best Boutique Guitar/Bass Pedal Brands To Know & Use

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Understanding Compression

It’s useful to understand how compression works in advance of purchasing a new compressor. In this section, we’ll run through the typical controls to watch out for when reading up on a prospective compressor.

The typical compressor parameters include:

Compressor Threshold

What is the threshold of a compressor? The threshold of a compressor is a set amplitude limit that dictates when the compressor will engage and disengage. As the input exceeds the threshold, the compressor kicks in (with its given attack time). As the input drops back down below the threshold, the compressor disengages (according to its release time).

Choosing a compressor with a large, adjustable threshold control will ensure that it will work with a greater number of input signal levels.

If you opt for a compressor with a small range of threshold control or no threshold adjustments whatsoever, you’ll have to do more work in the gain staging of the signal before it reaches the compressor’s input.

To learn more about compressor threshold controls, check out my article Dynamic Range Compression: What Is The Threshold Control?

Compressor Ratio

What is the ratio of a compressor? The compressor ratio compares the number of decibels the input signal is above the threshold to the number of decibels the output signal is above the threshold. In other words, it is the relative amount of attenuation the compressor will apply to the signal.

Put differently; compressor ratio is defined as [input signal dB above the threshold] : [output signal dB above the threshold].

More ratio controls mean more versatility in the process of dynamic range compression. Compressors may have switches between defined ratios (typically integer multiples) or a continuous dial that adjusts the ratio.

If the compressor offers high ratios (20:1 to ∞:1), it can practically act as a limiter.

Remember that lower ratios mean gentler compression, and higher ratios mean a more compressed or “squashed” sound.

Suppose it happens to offer ratios below 1:1. In that case, it offers what is known as “upward compression,” which is a type of compressor that boosts the amplitude of a signal below a certain threshold and keeps the amplitude the same above the threshold. This type of compression is available in digital plugins and can also be achieved via parallel compression with hardware or software.

To learn more about compressor ratio controls, check out my article Dynamic Range Compression: What Is The Ratio Control?

Compressor Attack Time

What is the attack time of a compressor? The attack time is the amount of time it takes for a compressor to engage/react once the input signal amplitude surpasses the threshold.

Choosing a compressor with fast attack values (<10 ms) will cause the compressor to act faster, which can lead to a thicker compression sound at the expense of transient reduction.

Choosing a compressor with slow attack values (>10 ms) will allow the track to breathe a bit while helping to shape transients. However, slower attacks aren’t so good at controlling dynamics and may contribute to audible pumping.

For the most versatility, look for a compressor with slow and fast attack times if possible.

To learn more about compressor attack time controls, check out my article Dynamic Range Compression: Attack & Release Controls.

Compressor Release Time

What is the release time of a compressor? The release time is the amount of time it takes for the compressor to disengage (to stop attenuating the signal) once the input signal drops below the threshold.

Choosing a compressor with fast release values (dependent on the rhythmic transients of the tracks or roughly <30 ms) will cause the compressor to disengage faster. This can sound more natural if the compressor isn’t applying too much gain reduction but can quickly start pumping if the gain reduction is more aggressive.

Choosing a compressor with slow release values (dependent on the rhythmic transients of the tracks or roughly >30 ms) will cause the compressor to disengage slower. This will help smooth out dynamics but may override the following transients that could re-trigger the compressor from 0 dB reduction. If the release time is too slow, it may have the effect of pushing the track further back in the mix by killing transients.

For the most versatility, look for a compressor with slow and fast release times if possible.

Some compressors offer auto-release settings, which aim to set the release time to a value that releases fast enough to catch following transient information and slow enough to keep the signal from pumping.

To learn more about compressor release time controls, check out my article Dynamic Range Compression: Attack & Release Controls.

Compressor Knee

What is the knee of a compressor? The compressor’s knee refers to the transition point around the compressor’s threshold where the output becomes attenuated versus the input. A hard knee offers a more distinct triggering of the compressor, while a soft knee allows for a smoother and more gradual transition to compression.

Compressor knee is often a characteristic of the gain reduction circuit itself, but some compressors offer adjustable knee values.

A hard knee will immediately engage the compressor (it’s still subjected to its attack time) as the signal surpasses the threshold. Similarly, it will disengage the compressor (it’s still subjected to its release time) immediately as the signal drops back below the threshold. Harder knee values cause more aggressive compression, which is great for more transient material (percussion, for example).

A softer knee will engage the compressor slightly before the threshold and roll the curve so that the full ratio is only achieved past the threshold. Softer knee values cause smoother compression, which is often better for less dynamic material (vocals, for example).

If you’re looking for versatility, a switchable soft/hard or continuously variable knee control will grant you some extra flexibility. If this parameter is not present, consider the gain reduction circuitry (or emulation) to gather information on the typical knee values associated with such GR circuits—more on this later in the section Compressor Circuit Types.

To learn more about compressor knee controls, check out my article Dynamic Range Compression: What Is The Knee Control?

Compressor Makeup Gain

What is the makeup gain of a compressor? The makeup gain of a compressor is the gain applied to the signal after the compression takes place. Makeup gain is typically used to bring the peaks of the compressed signal up to the same level as the peaks pre-compression, thereby maintaining the same peak level while raising the overall level.

Makeup gain is a great control for compressors to provide the user with another gain stage for output level control. This is especially useful for A/Bing the compressor effect by having the output at the same set level.

To learn more about compressor makeup gain controls, check out my article Dynamic Range Compression: What Is The Makeup Gain Control?

Compressor Auto-Gain

What is auto-gain in a compressor? Compressor auto-gain is a feature that automatically applies the proper amount of makeup gain to bring the peaks of the compressed signal up to the same level as the peaks of the input signal. It effectively applies makeup gain to match the gain reduction of the compressor.

This feature is useful for automatically adjusting the makeup gain, making the compressor more convenient.

Compressor Metering

What is compressor metering? There are typically three meters in a compressor that will show users the input level, amount of gain reduction and the output level of the compressor. Some compressors also offer a graphical analysis of the input vs. output levels complete with threshold, ratio and knee indicators.

Though the best advice I can give is to use your ears when making audio decisions, I must admit that visual monitoring aids are extremely valuable.

If the compressor has input and output level monitors, it makes adjusting makeup gain super easy. Gain reduction monitoring allows us to see how when the compressor is working and by how much. It’s also useful to associate certain sonic performance with defined settings and gain reduction values.

Compressor Lookahead

What is compressor lookahead? Lookahead is a control that allows a compressor to “see” the input signal before it is processed to handle transient information better and maintain a smooth attack. Lookahead is achieved by duplicating and delaying the incoming signal, using the first signal as a sidechain.

Lookahead control isn’t super common in compressors (though it’s super useful in limiters). However, it’s a feature worth considering when shopping for a new compressor since it can help smooth out the compression and catch particularly intense transients.

To learn more about compressor lookahead controls, check out my article Dynamic Range Compression: What Is The Lookahead Control?

Compressor Stereo Linking

What is stereo linking in a compressor? Stereo linking is a method for stereo compressors (or dual-mono compressors) to act on both channels of a stereo audio signal at once. If either of the stereo channels exceeds the threshold, the compressor will engage and attenuate both channels. This is a method to avoid tilting the stereo image.

Stereo linking is a superb feature to look for in stereo compressors. By linking the stereo signals, the same amount of compression will be applied to each channel (left and right). Compressing both channels the same way will lead to a more balanced stereo image in the compressor output.

Having the ability to engage and disengage stereo linking will offer the most versatility, depending on your goals. Perhaps you’re using the stereo compressor as a two-channel compressor with two independent mono tracks, for example. In that case, stereo linking would not be advisable.

Back to the Table Of Contents.


Compressor Circuit Types

There are plenty of compressor types (gain reduction circuits) on the market, and each of them will perform the process of dynamic range compression a bit differently. Each type tends to have some identifiable characteristics, though no two compressor models are exactly the same even if they share the same GR circuit type.

In this section, we’ll discuss the following compressor types to help you decide which is best for you:

Variable-Mu (Tube) Compressors

What is a variable-mu compressor? A variable-mu (variable gain) compressor is an analog compressor centred around a vacuum tube. As the input signal increases, the current sent to the grid of the tube decreases, which results in a reduction in the overall level.

Characteristics of a variable-mu (tube) compressor:

  • Relatively slow attack and release times
  • Slight harmonic distortion
  • Soft knee
  • Program-dependent ratio
  • Fewer parameter controls
  • Feedback sidechain circuit

For more information on variable-mu compressors, check out the following My New Microphone articles:
 What Is A Variable-Mu (Tube) Compressor & How Does It Work?
• Top 11 Best Variable-Mu Compressor Emulation Plugins

FET Compressors

What is a FET compressor? A FET compressor is an analog compressor that utilizes a field-effect transistor at the core of the circuit. These compressors are fast-acting and offer greater transient preservation than other types of compressors.

Characteristics of a FET compressor:

  • Very fast attack and release times
  • Non-linear compression that adds character via harmonic distortion
  • Additional saturation due to the inclusion of transformers
  • Requires low-level input signals
  • Requires more output gain which often raises the noise floor
  • Feedback sidechain circuit

For more information on FET compressors, check out the following My New Microphone articles:
 What Is A FET Compressor & How Does It Work?
• Top 11 Best FET Compressor Emulation Plugins For Your DAW

Optical Compressors

Optical Compressor

What is an optical compressor? An optical compressor is an analog compressor that uses a light element and optical cell to alter the dynamics of an audio signal. As the amplitude of the audio signal increases, the light element emits more light and causes the optical cell to attenuate the amplitude of the output signal.

Characteristics of an optical compressor:

  • Generally low distortion due to LDR
  • Relatively slow attack and release times
  • Non-linear attack and release controls
  • Frequency-dependent attack
  • Transparent sound
  • Feedback sidechain circuit

For more information on optical compressors, check out the following My New Microphone articles:
 What Is An Optical Compressor & How Does It Work?
• Top 10 Best Optical Compressor Emulation Plugins

VCA Compressors

What is a VCA compressor? A VCA (voltage-controlled amplifier) compressor is an analog compressor that utilizes a VCA control to apply compression. The input signal is split through an integrated circuit into a detector path (to control the VCA compression) and an output path.

Characteristics of a VCA compressor:

  • Very low distortion
  • Flexible threshold, ratio, attack, release and (sometimes) knee parameter controls
  • Transparent sound
  • Feedback or feed-forward sidechain circuit

For more information on VCA compressors, check out the following My New Microphone articles:
 What Is A VCA Compressor & How Does It Work?
• Top 11 Best VCA Compressor Emulation Plugins For Your DAW

Diode Bridge Compressors

What is a diode bridge compressor? A diode bridge compressor is an analog compressor that utilizes pairs of diodes in a balanced bridge configuration to apply variable attenuation (compression) to the input signal.

Characteristics of a diode bridge compressor:

  • Very fast attack and release times
  • Non-linear compression that adds character via harmonic distortion
  • Requires low-level input signals
  • Requires more output gain which often raises the noise floor
  • Feedback sidechain circuit

For more information on diode bridge compressors, check out my article What Is A Diode Bridge Compressor & How Does It Work?

Pulse Width Modulation Compressors

What is a pulse width modulation compressor? A PWM compressor is a type of compressor that utilizes pulse width modulation to effectively alter the amplitude of the input signal, thereby compressing it. Altering the parameters will alter the PWM system to control the amount of compression.

Characteristics of a pulse width modulation compressor:

  • Very fast attack and release times
  • Very transparent
  • Flexible parameter controls
  • Feedback of feed-forward sidechain circuit

For more information on PWM compressors, check out my article What Is A Pulse Width Modulation Compressor & How Does It Work?

Digital Compressors

What is a digital dynamic range compressor? A digital compressor is a digital signal processor that produces the effect of compression on a digital audio signal. Many digital compressor plugins and software aim to emulate their analog counterparts.

Characteristics of a pulse width modulation compressor:

  • Fast or slow attack and release times
  • Clean or saturated processing
  • Soft or hardknee
  • Program-dependent or defined ratio
  • Greatest number of parameter controls
  • Feedback or feed-forward sidechain circuit

Back to the Table Of Contents.


Compressor Features & Styles Of Compression

Now that we know the different types of compressors and the typical controls, let’s consider the general applications for compressors and the features we may come across.

When choosing a compressor to purchase, consider the following applications and features, how often you’ll need/use these features in your application, and how well the compressor in question will suit your needs.

In the section, we’ll discuss the following:

Bus Compression

The “bus” in bus compressor is generally the master bus of the mixer/console or DAW. These busses are typically stereo (having a left channel and a right channel) and often benefit greatly from “bus compression.”

Bus compression is often gentle in terms of their threshold, ratio, attack, release and even knee parameters. The trick is not to squash the dynamic range as much as it is to bring out nuances and add depth, colour and subtle movement to the track while helping to maintain a consistent level throughout the mix and avoid overloading.

There are plenty of stereo compressors on the market that are marketed as bus compressors. Look for a stereo compressor with a pleasing sound and the characteristics and parameters listed in this section.

Multiband Compression

What is multiband compression? Multiband dynamic range compression is a type of processing that splits the frequency spectrum into different bands and compresses each band by its own unique compression settings.

A multiband compressor can be thought of as several compressors in one, with each compressor acting on its own defined band of frequencies. Each band will generally have its own set of parameters, including threshold, ratio, attack, release and makeup gain.

MB compressors may be intimidating, but they are excellent tools for individual tracks and buses alike when used correctly. They can be set up to handle transients appropriately in defined frequency bands, reducing the pumping that may be caused fro excess energy in certain bands.

To learn more about multiband compression, check out the following My New Microphone articles:
What Is Multiband Compression & How Do MB Compressors Work?
Top 10 Best Multiband Compressor Plugins For Your DAW

Sidechain Compression

What is sidechain compression? Sidechain compression is a type of compression where the compressor acts to compress a track but is controlled by another track (the external sidechain). As the controlling signal surpasses the set threshold, the compressor attenuates the sidechained signal.

Technically all compression utilizes a sidechain signal, though this signal is typically derived from the input signal.

If the compressor has an external sidechain input, it means that a separate signal can control the gain reduction circuit that acts upon the compressor’s input signal.

Sidechain compression can really bring a mix to life, adding subtle colour and movement while “auto-mixing” certain elements together.

Sidechaining is also a popular mix technique made famous/infamous by the aggressive sidechaining to the kick of various elements in certain electronic music genres/mixes.

Consider a model with a sidechain high-pass filter if you’re looking for a compressor with external sidechain capabilities. The low-end of a sidechain signal may cause unwanted triggering of the compressor, and high-passing the signal can ameliorate this unwanted compression.

To learn more about sidechain compression, check out the following My New Microphone articles:
• The Complete Guide To Sidechain Compression In Audio
Audio EQ: What Is A High-Pass Filter & How Do HPFs Work?

Parallel Compression

What is parallel compression? Parallel compression (also known as New York or Manhattan compression) is a technique where one audio track (or several) is sent to a bus, which is heavily compressed. Both versions of the audio are then mixed together to achieve a punchy sound without losing the dynamic of the dry signal(s).

Though parallel compression can easily be achieved by duplicating a track to a bus and compressing one copy hard while leaving the other unaffected. However, a compressor with parallel functionality (mix control) is more convenient.

Series Compression

What is serial compression? Serial compression is the practice of using multiple compressors in series (one after the other) to combine desirable attributes from different compressors, lighten the workload on any particular compressor, and ultimately progress through an audio mix.

Serial compression is essentially the process of sending an audio track through multiple compressors, one after the other. A single hardware compress will generally only offer one compression stage, though two or more hardware compressors are perfectly capable of serial compression.

Generally speaking, each compression stage should have moderate settings. Oftentimes two different compressor types will be used to add two different styles of compression. For instance, a FET compressor could tame the peaks before a variable-mu compressor smoothes out the signal.

Though serial compression is a technique that can be used on individual tracks, it’s much more common in mixing at various bus stages. For example, a kick drum can be compressed at its track, at its drum mix bus, and at the master mix bus.

Serial compression is made easy with compressor plugins, which can be used in multiple instances within a digital audio workstation.

Peak Vs. RMS Compression

What is peak compression? Peak compression means that the compressor will react according to the peak of the input or sidechain signal. As the peak of the compressor control exceeds the threshold, the compressor will kick in.

What is RMS compression? RMS (root mean square) compression means that the compressor will react according to the “average loudness” of the input or sidechain signal. As the “average” of the compressor control exceeds the threshold, the compressor will kick in.

Peak compression tends to be more aggressive when engaged, though audio peaks are typically more short-lived than RMS values, so peak compressors will engage and disengage more rapidly. Peak compression is a superb choice for transient-heavy material like drums.

Limiters, which are often tasked with maintaining a maximum output level, are typically peak-controlled.

RMS compression is often more subtle and longer-lasting (given the same attack/release times) than peak compression, making it a superb choice for non-percussive instruments, singing and mix buses. However, because it only acts upon the average amplitude, RMS compression can potentially miss transient peaks in a signal completely.

If you’re looking for versatility, a few compressor options on the market offer both peak and RMS metering.

To learn more about peak and RMS metering, check out my article Peak Vs. RMS Dynamic Range Compressors In Audio.

Feedback Vs. Feedforward Compression

What is feedback compression? Feedback compression feeds the audio signal into the sidechain just after the gain reduction element. This compressor type reacts to the signal amplitude without anticipating.

What is feed-forward compression? Feed-forward compression feeds the audio signal into the sidechain before the gain reduction element. This compressor type anticipates the signal amplitude and adjusts the sidechain signal in advance.

Feedback compressors tend to be less precise, offer fewer parameter controls and exhibit more interdependence between the parameter controls. They aren’t capable of hard limiting but typically sound more natural with aggressive settings.

Feedback circuits are typically found in VCA, PWM, FET, optical, variable-mu, and diode bridge compressor circuits.

Feed-forward compressors generally offer more precise control with more parameters. Each parameter is typically independent of the others (within reason). Though feed-forward may sound more aggressive and can be used for hard limiting, it’s often chosen for its versatility.

Feed-forward circuits are typically found in VCA, PWM, and digital/plugin compressor circuits.

Some compressors will offer the option between the two sidechain feeds, and a few others will even have a blend control between the two options.

To learn more about feedback and feed-forward compression, check out my article Feedback Vs. Feed-Forward Dynamic Range Compressors In Audio.

Upward Compression

What is upward compression? Upward compression is a type of dynamic range compression that boosts the amplitude of an audio signal below a certain threshold while maintaining the amplitude above the threshold. Upward compression is available in digital plugins and via parallel compression with hardware or software.

Upward compression isn’t overly common but is worthy of mention in this article. If a compressor you’re interested in has upward compression capabilities, it can reduce the dynamic range by bringing up the lowest levels of the signal without affecting the peaks.

To learn more about upward compression, check out my article What Is Upward Dynamic Range Compression In Audio?

De-Essing

What is an audio de-esser? De-essing is the process of attenuating sibilance and/or harshness in a vocal/voice audio signal. This can be achieved using a dynamic EQ, multiband compressor, sidechain compressor with automation in a mix, or manually.

Though de-essers are often packaged as distinct hardware units or audio plugins, some compressors will have the option for de-essing.

Of course, it may be easier (and more effective) to use a dedicated de-esser rather than a compression (which is typically capable of much more). However, de-essing capabilities are worth considering when choosing your next compressor.

Back to the Table Of Contents.


Compressor Inputs/Outputs

Now let’s consider the inputs and outputs we may find on a compressor.

Audio input(s): the audio inputs are where the program audio is inputted to be compressed. The number of inputs will typically be equal to the number of channels the compressor offers (a mono compressor will have one input and a stereo compressor with have two inputs), though some compressors will offer different input connector options per channel.

Depending on the compressor design, the audio inputs may have the following connectors:

  • XLR-F 3-pin
    • balanced line level audio (pro audio compressors)
  • 1/4″ (6.35mm) jack
    • TS: unbalanced instrument level (compressor pedals and modular synth compressors)
    • TRS: balanced line level audio (pro audio compressors)
  • 1/8″ (3.5mm) jack
    • TS: unbalanced instrument level (modular synth compressors)

Sidechain insert(s): sidechain inserts offer a send and return path for the inclusion of external processing in the sidechain signal path (often en EQ). The typical connectors for insert send and returns are 1/4″ jacks.

External sidechain input(s): the sidechain inputs allow an external sidechain signal to be inputted to control the compressor circuit. Typical connectors include 1/4″ jack and XLR-F 3-pin.

Audio output(s): the audio outputs are where the program audio is outputted after compression. The number of outputs will typically be equal to the number of channels the compressor offers, though some compressors will offer different output connector options per channel.

Depending on the compressor design, the audio outputs may have the following connectors:

  • XLR-M 3-pin
    • balanced line level audio (pro audio compressors)
  • 1/4″ (6.35mm) jack
    • TS: unbalanced instrument level (compressor pedals and modular synth compressors)
    • TRS: balanced line level audio (pro audio compressors)
  • 1/8″ (3.5mm) jack
    • TS: unbalanced instrument level (modular synth compressors)

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A Note On Channel Strips

A channel strip technically refers to a single channel on a mixing console, though channel strips can be purchased as standalone, modular, and software units.

Channels strips generally have a mic input and mic preamp and can also include instrument (Hi-Z) and line inputs. Some channel strips offer a compressor section.

In addition to compression, channel strips may also feature EQ, gates, and even more, depending on the model. They’re designed to offer all the basic signal processes we’d need to record superb audio at the source.

Like compressors, channel strips come in a variety of formats. These formats include modular form factors for specific modular mixing consoles, 500 Series, desktop, and rackmount units. Channel strip plugins are also available for digital audio workstations.

Related My New Microphone article:
Top 11 Best Channel Strip Plugins For Your DAW

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This article has been approved in accordance with the My New Microphone Editorial Policy.

Arthur

Arthur is the owner of Fox Media Tech and author of My New Microphone. He's an audio engineer by trade and works on contract in his home country of Canada. When not blogging on MNM, he's likely hiking outdoors and blogging at Hikers' Movement (hikersmovement.com) or composing music for media. Check out his Pond5 and AudioJungle accounts.

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