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 certain controls affect the sound, and how the different types of EQ work.
Equalizers can be used 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 alter harmonics. But, you must bear in mind that by altering a separate instrument you will affect the mix. 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 instruments in the mix, which could result in poor clarity. This can happen due to a peak at a certain frequency that should be attenuated, or simply because there are too many instruments in the same frequency range. You must use the equalizer to attenuate or clear some frequencies in certain instruments to achieve more clarity in the mix. This problem is known as masking.
In this article, we’ll explain 4 types of equalization: Shelving, graphic, semi-parametric and parametric.
This type of EQ is the most simple and inexpensive and can be found in 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 similar to a Shelving EQ, with some differences in the back end.
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.
There are different types of graphic equalizers; the most common is the octave graphic equalizer, which has 10 frequency controls. This is 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.
The Parametric Equalizer is the most precise and versatile type of EQ because it lets you select the centre frequency you want to equalize, as well as the bandwidth and gain. There are also multi-band parametric equalizers, the most common is the 4-band parametric EQ. It is also the most complex equalizer of all and can be hard to set up when you don’t have a graphical representation (analog hardware).
This equalizer can be used as a filter to eliminate or attenuate unwanted frequencies, noise or interference. Such problems usually happen in a certain frequency range, so a parametric equalizer is ideal for this purpose.
This equalizer is similar to the parametric EQ. 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.
It’s up to you which type of equalizer to use. It’s good to learn how to use a parametric EQ because you will need to use it many times. Even if it can be difficult at first, you will benefit from its precision and versatility. So… which EQ do YOU like most? Leave a comment and let us know!
Post Images under Creative Commons Attribution License by Will Fisher.