The Ultimate Audio Equalizer/EQ Buyer’s Guide 2021


So you’re wondering which EQ 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 an audio equalizer.

If you’ve found yourself asking, “which EQ 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 equalizer/EQ buyer’s guide to help you in your next EQ purchase!

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


Table Of Contents


What Is Your Audio Equalizer/EQ 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.

Equalizers, 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 equalizer unit. For example, if the EQ is needed for business, perhaps stretching the budget is more appropriate. If, on the other hand, you don’t plan on making money with the EQ, perhaps a more conservative budget is appropriate.

Also, consider any additional accessories or upkeep that may be required for your audio equalizer.

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

Back to the Table Of Contents.


Audio Equalizer/EQ Hardware Vs. Plugins

When choosing an equalizer, it’s definitely worth weighing the option between a hardware EQ and an EQ plugin.

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

Equalizer plugins can be original designs, and digital processing and programming have made some of these EQs 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 EQ plugin can be inserted on as many audio track inserts as your DAW and CPU can handle, unlike hardware EQ 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 equalizer (or multiple) 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 EQ.

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

Back to the Table Of Contents.


Audio Equalizer/EQ Form Factors

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

Rackmount EQs

Rackmount EQs 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 EQs

Tabletop EQs 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 EQs

500 Series EQs 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 EQs

Though not as common as the other form factors, you may come across EQ 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 EQs

Studio/recording, broadcast and live mixing consoles can also be modular. There is a small market for modular EQ 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

Effects Pedal EQs

EQ pedals are relatively common for bassists and guitarists. You’ll often find equalizer pedals on pedalboards.

Related My New Microphone articles:
What Are EQ Pedals (Guitar/Bass) & How Do They Work?
Top 12 Best EQ 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

Vehicle-Mounted EQs

EQs are also popular inclusions in car audio. Though modern car stereos will offend handle the EQ of the car’s audio system, separate EQ units are also available than mount into the vehicle for more direct control over the frequency response.

Back to the Table Of Contents.


Understanding Filters

To understand EQ, we must understand the basics of filters. In this section, we’ll briefly discuss each of the filter types we’ll come across in EQ units/plugins:

High-Pass Filters In EQ

What is a high-pass filter in audio? A high-pass filter (HPF) “passes” the high-frequencies above their cutoff frequency while progressively attenuating frequencies below the cutoff frequency. In other words, high-pass filters remove low-frequency content from an audio signal below a defined cutoff point.

Frequency vs. Amplitude of a General High-Pass Filter

To learn more about high-pass filters, check out my article Audio EQ: What Is A High-Pass Filter & How Do HPFs Work?

Low-Pass Filters In EQ

What is a low-pass filter in audio? A low-pass filter (LPF) “passes” the low-frequencies below their cutoff frequency while progressively attenuating frequencies above their cutoff. In other words, low-pass filters remove high-frequency content from an audio signal above a defined cutoff point.

Frequency vs. Amplitude of a General Low-Pass Filter

To learn more about low-pass filters, check out my article Audio EQ: What Is A Low-Pass Filter & How Do LPFs Work?

Band-Pass Filters In EQ

What is a band-pass filter in audio? A band-pass filter “passes” a band of frequencies (a defined range above a low cutoff frequency and below a high cutoff frequency) while progressively attenuating frequencies below the low cutoff and above the high cutoff.

Frequency vs. Amplitude of a General Band-Pass Filter

To learn more about band-pass filters, check out my article Audio EQ: What Is A Band-Pass Filter & How Do BPFs Work?

Notch Filters In EQ

What is a notch filter in audio? A notch filter (aka band-reject or band-stop filter) removes frequencies in a specified band within the overall frequency spectrum. It allows frequencies below the low cutoff frequency to pass along with frequencies above the high cutoff frequency.

Frequency vs. Amplitude of a General Band-Stop Filter

To learn more about notch/band-stop filters, check out my article Audio EQ: What Is A Band-Stop Filter & How Do BSFs Work?

Bell Filters In EQ

What is a bell curve filter in audio? A bell curve filter can produce resonance (boost in EQ) or anti-resonance (cut in EQ) around a specified centre frequency. These filters are defined by a central frequency, Q factor (width of the boost/cut) and relative gain.

Frequency vs. Amplitude of a General Bell Filter Boost
Frequency vs. Amplitude of a General Bell Filter Cut

Shelving Filters In EQ

What is a low-shelf filter in audio? A low shelf filter is a filter that either boosts (increases amplitude) or cuts (decreases amplitude) frequencies below a certain cutoff frequency. These filters generally have a well-defined transition band and a levelling-off of amplitude in the lower end.

Frequency vs. Amplitude of a General Low-shelf Boost
Frequency vs. Amplitude of a General Low-shelf Cut

What is a high-shelf filter in audio? A high shelf filter is a filter that either boosts (increases amplitude) or cuts (decreases amplitude) frequencies above a certain cutoff frequency. These filters generally have a well-defined transition band and a levelling-off of amplitude in the upper end.

Frequency vs. Amplitude of a General High-shelf Boost
Frequency vs. Amplitude of a General High-shelf Cut

To learn more about shelving filters, check out my article: Audio Shelving EQ: What Are Low Shelf & High Shelf Filters?

Back to the Table Of Contents.


Audio Equalizer/EQ Types/Styles

There are plenty of equalizer types on the market, and each of them will apply EQ a bit differently.

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

Graphic EQ

What is graphic audio equalization? Graphic equalization is a style of EQ where predetermined bands, centred around set frequencies with set Q factor values, can be either boosted or cut. The name comes from the fact that the EQ settings of a graphic EQ unit typically look very obvious and “graphic”.

The graphic nature of graphic EQs makes them rather easy to use—what you see is what you get. There are no back menus to scroll through and no frequency dialling. The frequencies are set, and it’s simple to adjust them visually to our needs.

Graphic EQ units are popular in live sound systems when “tuning the room” is required. Audible feedback can be an issue, and a quick dip in one or more of the graphic EQ bands is often all we need to eliminate such feedback.

Graphic EQ is also popular in inline instrument EQs such as effects pedals. Again, they’re easy to dial in and visually represent the resulting EQ curve.

For more information on graphic EQ, check out the following My New Microphone articles:
The Complete Guide To Graphic Equalization/EQ
Top 8 Best Graphic EQ Plugins For Your DAW

Parametric EQ

What is parametric audio equalization? Parametric EQ offers full customization of the frequency bands, including the choice of filter type, centre frequency, Q factor value and relative gain (boost/cut).

Parametric equalizers are very flexible in their operation. Common parametric EQ parameters include:

  • Centre frequency of mid bands
  • Gain (boost/cut)
  • Q
  • Cutoff frequency of low-pass and high-pass filters
  • Slope of the low-pass and high-pass filters (not on all models)
  • Filter selection (low-pass or high shelf; high-pass of low shelf, etc.)

With parametric EQ, we can sweep the frequency of a parametric EQ and set it exactly where we need it to be. We can also control the Q parameter and, of course, the amount of gain.

Parametric EQs are common in studio EQ units and console channel strips. Parametric EQ is also one of the most popular types among EQ plugins.

For more information on parametric EQ, check out the following My New Microphone articles:
The Complete Guide To Parametric Equalization/EQ
Top 10 Best Parametric EQ Emulation Plugins For DAWs
Top 10 Best Digital Parametric EQ Plugins For Your DAW

Semi-Parametric EQ

What is semi-parametric audio equalization? Semi-parametric EQ (sometimes referred to as quasi-parametric EQ) offers some, but not all, of the customization of a parametric EQ. The customization of the frequency bands could include the choice of filter type, centre frequency, Q factor value and relative gain (boost/cut).

Semi-parametric EQ is perhaps more common than true parametric EQ in hardware units. Many equalizers will offer some fully parametric bands and some semi-parametric bands.

Semi-parametric EQ is common in mixers, consoles, pedals, plugins, and more.

For more information on semi-parametric EQ, check out the following My New Microphone article:
What Is Semi-Parametric Equalization/EQ In Audio?

Dynamic EQ

What is dynamic audio equalization? Dynamic EQ is a type of equalization where the EQ of certain frequencies is triggered dynamically as those frequencies surpass a set amplitude threshold in the audio signal. Dynamic EQ, like a compressor, will have threshold, attack and release settings to alter the EQ of a signal dynamically.

Though there are dynamic EQ hardware units, this style of equalization is easier to achieve in plugins. Therefore, most dynamic EQs will be plugins. These EQs are generally based on parametric designs.

By introducing dynamic to the EQ process, these equalizers will be far from static and react differently to different frequency bands. The boosts and cuts of the EQ are triggered by the dynamics of the input signal (much like a compressor) and react accordingly by adjusting the EQ of the signal dynamically.

Dynamic EQ is often substituted for multiband compression in a mix. It is also used to EQ tracks for more dynamic excitement.

For more information on dynamic EQ, check out the following My New Microphone articles:
The Complete Guide To Dynamic Equalization/EQ
Top 10 Best Dynamic EQ Plugins For Your DAW

Linear Phase EQ

What is a linear phase equalizer? A linear phase EQ is a type of equalization that does not alter the phase relationship of the source. There is no phase shift, and, therefore, the phase is “linear”. Achieving linear phase is not possible with analog circuits and has been made possible with computer coding.

By EQing a signal without changing its phase, there will be no unseen resonances or dips in the overall frequency response. The phase changes/cancellations apparent in typical “minimum phase EQs” tend to affect the frequency response around the set frequency points of the EQ, thereby altering the response in ways unintended by the controls.

Note that the phase changes, and the resulting weirdness around the EQ band, increase as steeper roll-off or Q values increase.

Linear phase EQs are made possible thanks to digital signal processing (DSP). These filters effectively analyze the frequency content of a signal and apply gain to the appropriate frequencies via FIR (finite impulse response) filters to eliminate any phase-shifting that arises. This high demand for processing means linear phase EQs are only practical in plugin programs.

Linear phase EQ is a superb choice for surgical EQ tasks where steep roll-offs and notch filters are required.

The side-effect of pre-ringing (where an echo will precede the intended output, particularly if this signal has strong transients) makes linear EQ a relatively poor choice for general EQ on percussive tracks.

For more information on linear phase EQ, check out the following My New Microphone articles:
The Complete Guide To Linear Phase Equalization/EQ
Top 10 Best Linear Phase EQ Plugins For Your DAW

Shelving EQ

What is shelving equalization? Shelving eq utilizes high and/or low shelf filters to affect all frequencies above or below a certain cutoff frequency, respectively. Shelving can be used to either boost/amplify or cut/attenuate and affects all frequencies equally beyond a certain point.

Shelving EQ is common in home and car stereo systems, in music playback systems, and in consumer-grade audio systems that offer EQ. Think of these controls as “bass” and “treble.”

Back to the Table Of Contents.


Audio Equalizer/EQ Inputs/Outputs

Many audio devices have rather extensive I/O possibilities (audio interfaces and AV receivers, for example). Equalizers are much simpler and typically only have audio inputs and outputs.

The connections for these audio inputs and outputs may differ depending on the equalizer and its applications:

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

EQs are often either mono or stereo. Mono EQs will have a single input channel and a single output channel, while stereo EQs will have 2 channels (left and right).

Note that some stereo EQs have mid-side processing. The M/S matrix will be incorporated into the EQ (to split the stereo input into mid and side channels for processing, and then back into left and right channels after processing), so the inputs and outputs will remain stereo (left and right channels).

Related My New Microphone articles:
What Is Stereo Equalization/EQ In Audio & How Does It Work?
What Is Mid-Side Equalization/EQ (Audio) & How Does It Work?

Back to the Table Of Contents.


Passive Vs. Active Audio Equalizers/EQs

There are plenty of audio devices that can be passive or active (speakers, mixers, equalizers). Most often, the terms refer to whether the device requires power (making it active) or not (making it passive).

When it comes to equalizers, the terms passive and active are in reference to the filters used within the EQ. Note that practically all EQs will require power to function properly.

Passive filters are made exclusively of passive components (resistors, capacitors, inductors, etc.).

Because there is no gain stage within a passive filter, the output is always lower than the input as the signal passes through the circuitry and frequencies are filtered out. Furthermore, there’s no impedance correction/buffer in a passive filter system, meaning that the source feeding to EQ will likely alter the EQ’s performance.

The greater the order (the steeper the filter), the worse the signal attenuation.

For all the signal loss, “passive” EQs will have a gain stage after the filters to apply makeup gain and return the signal to a healthy level similar to the input.

Active filters include active components (op-amps are the most common active components). These active components allow for unity gain (amplitude in equals amplitude out) and also act as buffers to improve the consistency of the filter performance (the connected source and load will have little impact on the filter’s performance).

Active EQs have inherent distortion in their filters, but despite this fact, they’re often more consistent. They have an easier time boosting signal and can have more aggressive filter cutoffs and resonances without severe signal degradation.

Passive EQs are often cherished for their character (especially those with tube makeup gain stages). Though the filters produce less inherent distortion, passive EQs are typically more coloured due to the passive components and lack of impedance buffering. They’re also typically gentler and/or wider in their abilities since higher-order filters (steeper roll-offs and Q values) are impractical.

Digital EQ is technically active as well, though EQ algorithms are completely different than physical filters. As discussed with dynamic and linear phase EQ, digital programming can achieve much more than active and passive circuits!

Related My New Microphone article:
• The Complete Guide To Passive Equalization/EQ

Back to the Table Of Contents.


Number Of Bands In The Audio Equalizer/EQ

When choosing your next EQ, it’s important to consider the number of bands.

Each band in an EQ is its own filter, which can adjust the overall tone and frequency content of a signal.

The more bands, the more precise and complex the EQ graph can be. More bands also tend to mean a higher price point, though the price is also relative to the EQ type (graphic EQ bands are less expensive than parametric bands, for example).

Graphic EQs tend to have the most bands, though these bands are at fixed frequencies and often fixed Q values. Of course, the more bands available, the higher the resolution of the resulting equalization graph.

Parametric and semi-parametric EQs can be tricky. Make sure you know how many full parametric, semi-parametric, shelving, and HPF and LPF there are before making a decision.

Many EQ plugins will offer more bands than we’ll typically need. Consider these EQs if you need precise and/or complex EQ graphs.

If you only need general bass, mids and treble controls, consider a simple 3-band EQ.

Back to the Table Of Contents.


Typical Audio Equalizer/EQ Applications

Audio Equalizer/EQ For Recording Studios

Recording studios, where audio mixing and mastering take place, will often benefit from having the widest variety of equalization possible.

Many consoles have been designed with semi-parametric or parametric EQs, which allow for finer tuning of EQ.

Graphic EQs aren’t as common but are useful in adjusting an overall mix and/or tweaking the room acoustics.

Linear phase EQ is a superb tool for surgically removing problem frequencies in individual tracks and mixes.

Dynamic EQ is useful in various situations, helping to shape the tone of a track while also controlling its dynamics.

Shelving EQ is used in mixing to brighten tracks, move them forward or back in the mix’s depth, and enhance or reduce the low-end of tracks without completely eliminating low-end information.

In modern studios, EQ plugins often reign supreme, with hardware EQs often only tasked with recording signal chains and master bus processing.

Audio Equalizer/EQ For Live Sound & Public Address

When it comes to live sound, graphic equalizers are very popular tools. They help “tune the room” by easily cutting the problem/resonant frequencies of the acoustic space. They’re also typically outboard units, making it easy to see and adjust the overall EQ on the fly, rather than scrolling through menus on a digital board or reaching for EQ knobs on an analog board.

As for the live mixing consoles, digital EQs in digital boards are superb (typically parametric). Analog boards will generally offer a semi-parametric EQ in each of the channel strips.

Audio Equalizer/EQ For Car Audio

Car audio EQ is often handled by the stereo, with bass, mids and treble controls.

However, dedicated car equalizers do exist and are typically graphic or have fixed frequencies.

Back to the Table Of Contents.


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. There are plenty of channel strips that offer an EQ section as well.

In addition to EQ, channel strips may also feature compression, 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 equalizers, 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

Back to the Table Of Contents.


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.

Recent Posts