Types of EQ – Why you Should Only use One

I’m sure most of you have used EQ controls many times: on a stereo, instrument, amp, etc. But, there’s a lot of misunderstanding about how specific controls affect the sound and how the different types of EQ work.

Producers use equalizers to change the character or the sound of an instrument. To do so, you have to alter the harmonics or the fundamental frequency. Additionally, you can also use an aural exciter to change harmonics. But, you must bear in mind that you will affect the mix by altering a separate instrument. Usually, it is more important how the instrument sounds in the mix than by itself.

So, even if an instrument sounds good individually, it may interfere with other elements in the mix, resulting in poor clarity. This interference can happen due to a peak at a particular frequency that should be attenuated or simply because too many instruments are in the same frequency range. You must use the equalizer to attenuate or clear some frequencies in specific instruments to achieve more clarity in the mix. This problem is known as masking.

Some equalizers are better at doing this job, but others are simpler to use and visualize. However, with new technology, you can get the best of all by using a parametric EQ with graphic visualization.

What types of EQ are there?

This article will explain four types of EQ: Shelving, graphic, semi-parametric and parametric. Each is used in different fields and situations, knowing to use them all is important to be able to work in all scenarios.

Shelving EQ

This type of EQ is the most inexpensive and straightforward and is part of any common equipment such as a stereo or Hi-Fi. It offers the possibility to control the bass and treble, and sometimes it also has a «Mid» control. You can increase or decrease the gain, but the central frequency and bandwidth are fixed. This type of equalizer is less commonly used in professional audio but can be a simple way to control EQ. I’m sure you’ve seen this type of equalizer in many analog mixers. MasteringBOX EQ Control is visually similar to a Shelving EQ, however, it is actually a parametric EQ, though the central frequency and the Q parameters are dynamically set by our algorithm.

Graphic Equalizers

Graphic Equalizers were most commonly used in professional recording in the 20th century, given their versatility and ease of use. However, they are not as precise as the parametric equalizers and nowadays are not that common. They are still used mostly for PA calibration in live venues or concerts.

There are different types of graphic equalizers; the most common is the octave graphic equalizer, which has ten frequency controls. These frequency controls are pretty consistent because the audible bandwidth runs 10 octaves: 30 Hz, 60 Hz, 125 Hz, 250 Hz, 500 Hz, 1 kHz, 2 kHz, 4 kHz, 8 kHz, and 16 kHz. It is in those frequencies where we can increase or decrease the intensity of the audio signal.

Parametric EQ:

The Parametric Equalizer is the most precise and versatile of the types of EQ because it lets you select the center frequency you want to equalize and the bandwidth and gain. There are also multi-band parametric equalizers, which is usually the norm, being a 4-band parametric EQ the most common. It is also a complex equalizer and can be hard to set up when you don’t have a graphical representation (analog hardware). Although, nowadays it is very easy to use in digital mixers or computers with the graphic view.

With a Parametric EQ, you can also choose the type of filter. It can be low-pass, hi-pass, band-pass, notch, etc. This way you can eliminate or attenuate unwanted frequencies, noise, or interference. Such problems usually happen in a specific frequency range, so a parametric equalizer is ideal for this purpose.

Semiparametric equalizer:

This equalizer is similar to the parametric EQ, and it allows you to select the frequency you want to equalize and the gain. However, unlike the Parametric EQ, you cannot change the allocated bandwidth. These types of EQ are very rare and outdated.

Conclusion: Which one of the types of EQ should I use?

It’s up to you which type of equalizer to use. But for me, you should be using multi-band Parametric EQ whenever you have the choice. There are plenty of Parametric EQ plugins for Windows and Mac, it can take a bit to learn how to use it properly but you won’t regret the time spent. You will end up using it all the time and offers the most versatility and precision. So which type of EQ do YOU like most? Leave a comment and let us know!

Post Images under Creative Commons Attribution License by Will Fisher.