A Brief History of Equalization

But don't worry if you're feeling overwhelmed by all the knobs and dials; we've got your back! In this article, we'll take a look at the history of equalization in music production, from its first use in radio broadcasting up until today's digital EQs. We'll also discuss some common applications for EQs in modern music production, as well as tips on how best to use them so you can get great results every time! So let's dive into this fascinating world of audio manipulation - because after all, nobody likes a flat-sounding mix!

History of Equalizers - From Radio Broadcasting to Digital EQs

Equalizers have been an essential tool in music production for many decades. They are used to fine-tune sound frequencies in a mix, allowing producers to create unique effects and sculpt the sonic landscape of any track.

Radio & Television and the Roaring 20s

The first equalizers were developed in the early years of radio broadcasting in the 1920s. At the time, radio engineers used electro-mechanical equalizers to selectively boost or reduce frequencies in audio signals. These early equalizers were large and cumbersome, with rows of knobs and dials for each frequency band: They were primarily used in radio broadcasting to balance out the audio signal. One of the earliest examples of a electro-mechanical equalizer was the RCA 8B, which was first introduced in 1931. This device featured eight separate frequency bands, each with its own control knob.

As music recording techniques improved in the 1940s, equalizers began to find their way into recording studios as well. For example, in 1945, engineer Peter Goldmark developed the world's first commercial LP vinyl record, which featured a high-frequency boost of 20,000 Hz. This boost was achieved using an equalizer, and it helped to set the standard for records that followed.

In the 1940s it was Les Paul among the first to experiment with multitrack recording, and he used equalizers extensively to sculpt the sound of his recordings. One of his best-known tracks, "Lover," features a signature EQ effect known as "the Les Paul squawk," which was achieved by boosting a narrow frequency band around 4 kHz.

A very innovative user of equalizers during this period was Sam Phillips, the founder of Sun Records. Phillips was known for his unique approach to recording, which often involved using unconventional equipment and techniques. One of his most famous recordings was Elvis Presley's "That's All Right," which featured a distinctive echo effect that was created by running the signal through an equalizer and then sending it through a tape delay unit.

Motown & Beat in the 50s and 60s

In the 1950s and 60s, there was a new generation of EQs to be developed. These EQs used electronic circuits to selectively boost or cut frequency ranges, offering greater precision and control over the audio signal. These EQs were widely used in recording studios to shape the sound of the music of the decades. One of the most famous early electronic equalizers was the Pultec EQP-1A, which was introduced in the 1950s. This EQ was used extensively in the 1960s by producers such as Phil Spector on his famous "Wall of Sound" recordings. The Pultec EQP-1A was known for its unique sound, characterized by a "warm" and "round" sound quality and its great usability.

Another iconic electronic equalizer from the 1960s was the Neve 1073. This equalizer was developed by Rupert Neve, who is widely regarded as one of the most important figures in the history of audio equipment design and later found its place in large mixing consoles too.

Some sound examples of the era include "God Only Knows" by The Beach Boys, which features extensive use of the Pultec EQP-1A, the Rolling Stones' "Gimme Shelter," which was recorded using the Neve 1073, and "Stairway to Heaven" by Led Zeppelin, which was mixed using a combination of different vintage EQs from the 50s.

The wild 70s

Graphic equalizers became widely popular in the 1970s, and have been used by countless producers and engineers to sculpt the sound of their mixes. One famous example is the use of a graphic equalizer on the snare drum in Led Zeppelin's "When the Levee Breaks." Producers Jimmy Page and Andy Johns wanted a massive, booming sound for the snare, and achieved it by recording in a stairwell and using a graphic EQ to boost the low frequencies and cut the highs. This gave the snare a huge, thunderous sound that became a signature of the song.

Another producer known for using graphic EQs extensively is Brian Eno. In his work with artists like David Bowie and Talking Heads, Eno used graphical EQs to create complex, layered soundscapes. He would often use multiple EQs on individual tracks, boosting and cutting different frequencies to create unique textures and tonal characteristics.

More recently, producers like Max Martin and Dr. Luke have used graphic equalizers to craft chart-topping pop hits. Martin, in particular, is known for his attention to detail when it comes to EQing. He meticulously fine-tunes every element of his mixes, using graphic EQs to ensure that every instrument and vocal sits perfectly in the mix. This attention to detail has helped him craft some of the biggest pop hits of the last two decades, from "Baby One More Time" to "Dark Horse."

Whether you're working on a classic rock track, an experimental ambient piece, or a modern pop hit, graphic equalizers are an essential tool in any producer's arsenal. By carefully selecting and adjusting the frequency ranges, producers can shape and sculpt their mixes to achieve the desired effect, creating unique and unforgettable sonic landscapes.

Colorful 80s

The 1970s but especially the 1980s saw the advent of parametric equalizers. These EQs allowed engineers to adjust the center frequency, bandwidth, and amplitude of each frequency range, providing even greater precision and control over the audio signal. The use of parametric equalizers became synonymous with professional recording studios and high-end audio systems. The 80s were a decade of innovation and experimentation when it came to equalizers and their usage in music production. One of the most successful and popular parametric equalizers from this era was the SSL E Series EQ. The Solid State Logic (SSL) E Series EQ was a favourite of many producers and engineers due to its tight and precise control over the audio signal, allowing for parts of the audio to be isolated and modified in a surgical way. SSL E Series EQ was used extensively in the production of Michael Jackson's "Thriller" album, as well as on the tracks of many popular 80s artists including Madonna, Prince, and Bruce Springsteen.

During the 80s, producers also experimented with other types of equalizers, such as the dynamic equalizer. The dbx 905 was one of the most sought-after dynamic equalizers of the 1980s. This unit allowed producers to control the frequency response of a signal dynamically, responding to the input level of the audio. This technique was used to "compress" the sound on certain frequency ranges and gave producers more control over the amount of sound that was present, similar to the way compressors work. The dbx 905 was used extensively in the production of Depeche Mode's Music for the Masses and "Like a Prayer" by Madonna.

Many popular 80s songs utilized equalizers in innovative ways. The use of equalizers in "Sweet Child O' Mine" by Guns N' Roses, for example, helped to achieve the iconic guitar sound that is still emulated by many musicians today. "Billie Jean" by Michael Jackson utilized an SSL E Series EQ to achieve the distinct, crisp snare drum sound that is still one of the most recognizable in music history. The equalizer was also used extensively on the bass guitar and vocal parts, giving the song a sound that was both tight and punchy.

Current State-of-the-art

In recent years, digital equalizers have become increasingly popular. Digital EQs offer unparalleled precision and flexibility, allowing producers to precisely sculpt each individual frequency range. Digital EQs are often used in conjunction with computer software and audio plugins, offering incredible flexibility and control over the sound of music. The 90s saw the emergence of digital signal processing, which led to the development of more advanced equalizers. Audio plugins offered producers unprecedented precision and control over the audio signal, allowing them to shape and sculpt their mixes with extreme accuracy. Such advanced digital plugins have been used extensively in the production of many popular songs from the 90s, including "Waterfalls" by TLC, and "One" by U2.

Another popular equalizer from the 90s was the Avalon VT-747SP. This unit combined a parametric EQ with a compressor, allowing producers to shape the sound of their mixes in a variety of ways. The VT-747SP was used on a wide range of tracks from the 90s, including "Say My Name" by Destiny's Child, "Wonderwall" by Oasis, and "Changes" by Tupac.

As we entered the 2000s, digital audio workstations (DAWs) became increasingly prevalent, leading to a proliferation of digital EQ plugins. One of the most popular plugins from this era was the FabFilter Pro-Q. This EQ offered producers an intuitive and visually-oriented interface, allowing them to quickly and easily shape the sound of their mixes. The FabFilter Pro-Q has been used on many popular songs from the 2000s and beyond, including "Rolling in the Deep" by Adele, "Bad Guy" by Billie Eilish, and "Old Town Road" by Lil Nas X.

BUT: In recent years, there has been a resurgence of interest in vintage equalizers, with many producers seeking to recreate the sounds of classic recordings from the 60s, 70s, and 80s. One of the most sought-after vintage EQs is the Pultec EQP-1A. This EQ was originally designed in the 1950s and is prized for its warm, low-end boost and smooth top-end attenuation. The Pultec has been used on countless classic recordings over the years, including "Bohemian Rhapsody" by Queen, "Hotel California" by The Eagles, and "Thriller" by Michael Jackson.

Equalizers have become an essential tool in modern music production. They are used to enhance the clarity, balance, and tonal characteristics of music, providing the foundation for modern audio production. Whether you are a professional engineer or a hobbyist producer, the use of EQs is essential for achieving great sound. So remember, the next time you hear a great-sounding mix, it's likely that an EQ played a major role in creating that sound.

Overview of Equalizers and their Role in Music Production

Equalizers are the unsung heroes of the music production world. Without equalizers, our favorite songs would sound like a hot mess. But let's face it, equalizers have a major impact beyond just making music sound good - they basically shape our emotions by adding to the overall vibe of a song.

For example, if you want to convey a sense of excitement, you might boost the high frequencies to give the track a sense of brightness, clarity and energy. Alternatively, if you want to create a more relaxed atmosphere, you might reduce the high frequencies to make the mix sound softer and more laid-back. Who knew that twisting a few knobs on an equalizer could change our entire mood or allowing us to enter a world of psychedelic sounds (envelope filters)?

Equalizers are like the magic wands of music production that will "affect". They can turn a boring mix into a masterpiece, and transport us to a whole other dimension of sound.

Types of Equalizers - Parametric, Graphic, Shelving, etc.

Equalizers come in a variety of types and principles, ranging from basic analog filter cascades to complex digital plugins. From parametric EQs that allow you adjust gain, frequency and bandwidth with pinpoint accuracy, to graphic equalizers which let you draw your own curves - there's an equalizer for every situation. Then there are multi-band shelving EQs that can boost or cut entire ranges of frequencies at once like a surgeon wielding their scalpel, allowing producers to tailor their sound to perfection. Even more advanced audio plugins offer both linear phase processing and dynamic behavior so you can tweak anything from low end rumble all the way up to high end bite.

Parametric Equalizers

Those are the most common type of equalizer, often used in both live sound and studio recording. They offer greater control over the frequency spectrum, allowing you to fine-tune individual bands with extreme precision. Parametric EQs come equipped with adjustable filters that let you modify the gain, bandwidth, and center frequency of each frequency band. This makes it ideal for complex and detailed sound shaping and surgical sound correction.

Graphic Equalizers

Come with feature fixed-frequency bands that don’t allow for the same fine-tuning as parametric EQs. However, graphic EQs offer a simpler approach to equalization, making it perfect for smaller sound systems or those less intimate with the parameters of frequency equalization. Graphic EQs are usually built with a range of frequencies found within human hearing, usually groupings of 10-12 bands, and are arranged like a graph. They’re generally viewed as a simple, reliable solution, allowing users to visualize their sound as they work with the EQ controls.

Shelving Equalizers

Work with frequency ranges that extend beyond a fixed frequency band. They can shape the entire frequency spectrum, allowing sound engineers to create long, smooth curves within frequency ranges or set sharp, steep slopes and jagged curves. Shelving EQs can cut or boost sound frequencies, but they can’t take on individual bands. They can be used to alter the timbre of sound or the balance between low, mid, and high frequencies, creating staggering new tonal characteristics.

Fixed Band or Graphic Equalizers

Are the simplest form of EQ. They allow for a limited amount of control over the frequency spectrum but are often the most user-friendly for people new to sound engineering. However, fixed band equalizers don’t offer the same level of accuracy that parametric or shelving equalizers do.

Digital Equalizers

Represent the latest development in equalization technology. They offer a range of features that the analog counterparts do not. For example, digital EQs can use computer-based processing algorithms to create curves that are far smoother and more precise than what analog equipment is capable of. They’re much more reliable and have the ability to save hundreds of EQ settings as presets for later use. They’re also able to refine audio material to a more nuanced degree, resulting in more refined and accurate results than you might expect from analog equipment.

Common Applications for EQs in Music Production

Corrective Equalization

One of the primary uses of equalization in music production is corrective EQ, where the engineer uses it to fix issues with audio recordings. This type of EQ is used to remove unwanted frequencies and address issues such as resonant frequencies, muddiness, and harshness in the mix. By removing these issues, the engineer can achieve a clean and clear mix for the listener.

Tonal Equalization

Tonal equalization involves using EQ to change the tone or color of an audio recording. This approach is also known as color EQ and is used to add character and personality to sound recordings. It is commonly used when mixing individual tracks, such as bass, drums, guitar, and vocals.

Creative Equalization

Creative equalization involves using EQ as a creative tool to add unusual and unique sound effects. This type of EQ is usually used in sound design and film score production. For example, an engineer can use EQ to create a deep, booming sound effect or perhaps an ethereal and airy sound to generate space and depth in the mix.

Mastering Equalization

Mastering equalization is used to finalize the overall tonal balance of a mix, shape the sound of the master output, and make it ready for distribution. The mastering engineer uses EQ to balance the low, mid, and high frequencies, and make minute adjustments to dynamic range and harmonics to ensure it's consistent and pleasing to the listener.

Equalizers are some of the more versatile tools in music production that will have huge impact on sound and song perception. Applying EQ helps engineers to address audio issues, change tone, add creativity, and finalize the tonal balance. Therefore, it is crucial to have a strong understanding of how to use them to achieve the desired result.

Tips and Tricks for Using an EQ Effectively

Using HP and LP Filters Cutting the

low end and high end of a mix is one of the most effective ways of creating an excellent mix. The low-pass (LP) and high-pass (HP) filters are excellent tools for engineers to use to accomplish this task not only on a per channel basis, but often on a whole mix to give any song a final frequency boundary. HP filter help to rid of unnecessary bass and sub-bass frequencies, as many microphones will provide you with a load of unwanted info at the very low end, while LP filters are excellent at removing noise and hiss from tracks, especially when signals have been recorded in noise environments.

Frequency Notching

While equalization is often about boosting or cutting frequencies, sometimes, it's much more effective to notch a specific frequency range. This method is known as frequency notching. It entails tightly reducing a selected frequency range without affecting other parts of the mix. This method could be quite useful when addressing resonant frequencies or feedback during live performances, but is extensively been used when mixing drums (eleminating the often unwanted first or second overtone) or on vocals (de-essing).

Utilizing EQ Match Functionality

Taking advantage of EQ Match functionality can be super useful when trying to match one track's EQ to another track or during post-production mastering. The function analyzes a reference for its spectral distribution and matches the frequency response and other characteristics exactly or partially in the target track. This is a very cool feature that has come to the table with the digitalization of music production tools. It's also a helpful method for adjusting over a variety of song.s

Use Reference Tracks for Comparison

Using reference tracks is an excellent way to compare your mix with professional mixes. This method can help you identify and correct potential issues with your mix. A/B testing is one approach you can utilize when using reference tracks to analyze differences, especially when EQing.

How to determine which EQ to use in your music production

Equalization has been an integral part of music production since the 1930s when the first passive EQs were introduced. Today, the use of equalizers is ubiquitous with a wide range of types and designs available to choose from. Choosing the right EQ for a specific project can be a daunting task, but with a little guidance, it's simply a matter of understanding your options and knowing what you need.

Think of: What is the primary purpose of that EQ? And second: What is the degree of influence or reach of that EQ? - Is it going to be a Corrective EQ, that is used to fix a bass drums issues by reducing unwanted frequencies, or is it a subgroup EQ, that will have an influence on the sound of an instrument or section altogether. Does the EQ need to be a surgical tool or a boosting unit? Will I clean sound or will I enhance sound. A lot of topics that require for different EQ setups or functionality. And sure, most EQs will give that all, especially in the digital domain, but, some units have just been created for a specific purpose and do magic in that regard.

If you want to expand on your knowledge and arsenal of methods: Try to experiment with the huge amount of analog EQs and their emulated counterparts available, as this will sharpen your ear to the very detail. A can-do-it-all digital plugins sometimes is just not the right thing and from those "old" units sometimes there will be character added to a mix. Utilize the knowledge about existing best-practices and tools in order to re-create or invent sound confidently. With your own practice and following the best practices of a hundred years of mixing, you'll develop an ear for what works best in every mixing situation.