EQUALIZER AND EQUALIZATION.
Today we will be covering one of the most discussed music effect, the EQ.
Equalization is a very important process that gives the last touch to the song to let it became something brilliant, so it is very recommended that you get the understand the EQ and Equalization process. Once you get it you’ve just made 10 step forward, so be determinate and learn because at time it can be boring!
I’ll try to keep it simple and make you understand the functions, bands, frequency and any other thing that an Equalizer can do.
We can start saying that an Equalizer is a filter or effect that when producing music allows us to increase or decrease the decibel (volume) of certain frequencies, so that we can adjust the sound to have a better outcome for the listener.
An EQ offers different functions which are generally three:
Amplitude, Centre Frequency and Bandwidth.
Before we move forward, i want to make sure that you know what the Amplitude, Frequencies and Bands are, so that we both are on the same page. This will help you also getting a general understanding on EQs so that you can feel confident with any of them, because there are a few types. You could come across a Parametric EQ or a Graphic EQ, we will mention them later.
The term “Amplitude” is pretty simple to understand. It basically stands for the volume (Decibel) of each band. So an example if i have an Equalizer with seven band i can increase or decrease the volume of each band independently without effecting the main output volume.
Centre Frequency and Frequencies.
Let’s clear up the term “Centre Frequency”.
In the moment that you select a certain frequency, for example + 1 db on the Band of the “Bass range frequencies” and select the 186 Hz, if you draw an horizontal line from the decibel column on to the graphic and connect it with a vertical line that comes from the frequencies’s index column, the point where the two lines meets is the “Centre Frequency” point.
Some Equalizers interface will already guide you and subdivide the frequency so that you know which ones they are, but not all EQs offers this intuitive interface.
You need to know that our hearing organs allows us to hear sound frequency from about 20 Hz. to about 20.000 Hz.
We can subdivide this frequency from the lowest (20Hz.) to the highest (20.000 Hz.)in :
Sub-Bass (16 Hz. to 70 Hz.)
These frequency are the lowest frequency that you can get. More then hearing them you will feel them. Sub-Bass frequency can give to your mix a powerful feeling, if increased but don’t get to carried away other wise you’ll mess the mix up.
Bass (70 Hz to 260 Hz).
When modifying the EQ on this range, the user can change the balance of the mix making it fatter or thinner if increasing or decreasing the frequency.
Low Mid (260 Hz to 2.000 Hz).
This range is pretty big and we can, one more time, subdivide it!
From 260 Hz. to 500 Hz. : between this range we can let instruments with low frequency have more clarity.
From 500 Hz. to 2.000 Hz. : within this range, instruments like guitar or saxophone, which have a mid range sound, can really be boosted up so that they have more accent.
High Mid (2 kHz to 4 kHz).
This range contains all the main frequencies that we can hear the most, like rhythm instruments or even percussion. It’s up to the user to decide the audibility of the sound.
Presence (4 kHz to 6 kHz).
This frequencies range is pretty important because it can make the mix completely change. When increasing the frequency, the mix will sound more closer to the listener, vice versa when decreased .
Brilliance (6 kHz to 20 kHz).
The last range “Brilliance”, contains mostly harmonics and if boosted too much can create clipping or unwanted sound, so when equalizing , keep an eye on the main output. Let’s say that if you increase to about 12.000 Hz. it will give an Hi Fi sound.
BAND and BANDWIDTH.
Once you got the frequencies we can move to the next step which is “Band”. A Band is a certain knobs or slider that allows us to increase or decrease the pitch of the frequencies. Some EQ have 3, 5, 7 or even 21 and 30 Band. This means that an EQ containing 30 Band will allow us to control each Band with a knob or a slider.
The “Bandwidth” is the width of the band. It can be changed by the user making it “narrow” or “wide”. If we keep it narrow, this will mean that we are working on a limited frequencies range. If we increase the bandwidth, we will work on the main chosen frequency (centre Frequency) and all the other frequencies surrounding the one.
PARAMETRIC AND GRAPHIC EQ.
A Graphic EQ send input signal(s) trough a bank of filter, then each filter passes the portion of frequency in its own range depending on what the user does.
Graphic EQ can have 1 or 2 input. If it presents two set of sliders like in the photo, that will mean that the input signal (song) can be sent to both channel to simulate the Left and Right.
When presenting only 1 set of sliders, it will mean that the input signal is sent only trough one channel and the left and right will be summed together.
The sliders are there to adjust the Amplitude so that we can boost or cut the frequencies that we want. Graphic EQ can have 7 Band (sliders), 15, 25 or even 30, it all depends from the brand and the model. The knob of the slider represents the Centre Frequency.
In a Graphic Equalizer you won’t find such a function for Bandwidth. The Bandwidth will be adjusted by moving the knobs and looking at the graphic of the knobs to understand the selected bandwidth.
Parametric Equalizer are multi-band variable, that means that they allow us to control the three primary setting of the equalization process: Amplitude, Centre Frequency and Bandwidth.
Since all the main parameter can be adjusted, the Parametric Equalizer is the most effective and precise EQ. It really allows us to shape the frequencies, giving the preferred sound, very useful for mixing.
The Bands can be multiple, some has 5,7,10 etc.
It has HIGH pass filter (HPF) and LOW pas filter (LPF).
The user can really feel free to manipulate all the frequencies as he likes.