Pro Tools Tutorial Lesson 6 - EQ

In this video we will discuss basic EQ using the stock eq that comes with Pro Tools; by the end of this video you will know what the purpose of an equalizer is and how to set up high pass filters on your instruments.

What is Equalization?

     EQ (or equalization) is the process of changing the balance of different frequency components in an audio signal. The human hearing range is about 20Hz to 20,000Hz, and each frequency has a different impact on how sound is perceived. Lower frequencies could give a sense of calmness, while really high frequencies could cause headaches and pain.

SO...

     EQ is the tool we use to manipulate the frequency content of a sound source. Imagine a volume knob for a group of frequencies which you can turn up and down depending on what your needs are. That group of frequencies can be represented in sections called the Frequency Spectrum Division.

EQ in Mixing

          Musical instruments have a very unique sound that makes them stand out from each other. An electric guitar and an acoustic guitar have a very different sound, even when they play in the same frequency range; that is what we call timber. When playing the two together we could notice that they overlap, that overlap is called Masking. EQ is the tool we use in the studio to help reduce that effect.

EQ in Live Sound

         In live sound EQ has a different roll since a Front Of House engineer is playing with live instruments and loud SPL levels will cause feedback. EQ is used more as a defensive tool to prevent feedback. The main job of a FOH engineer is to amplify what's happening on stage, so the creative EQ is limited and at the artist's discretion. 

Simplified tip

EQing doesn’t create new frequencies. Think of EQing as sculpting a raw sound. 

Parts of an EQ

         There are many different types of equalizers out there, and most of them share the same parts. In this case we will talk about the EQ3 7 Band that comes stock in Pro Tools. This EQ is a parametric equalizer and is the most used type of EQ in the studio and new digital consoles.

The EQ3 7band has 7 bands that cover the whole frequency spectrum division; Low, Low Mids, Mids, High Mids, Highs plus low and high pass filters.

Filters

Filters allow you to cut out everything above or below a certain frequency. See them as a way to group frequencies, so they can be turned up or down in volume.

A High Pass filter will cut all the low frequencies below the frequency set.

Shelves attenuate or boost everything above or below a certain frequency by a set amount

Bell curves cut or boost a frequency and its surrounding frequencies at a set point. 

Control Parameters

Most EQs have the same parameters as the EQ3 7 Band.  Every Equalizer needs a Frequency, Gain, and Q knob. These parameters will allow you to manipulate your filters with clinical precision.

Frequency knob: Allows you to adjust the frequency for the selected band.

Gain Knob: Allows you to cut or boost the filter selected. This knob is disabled when using the low/high pass filters.

Q Knob: Controlls the bandwidth by allowing you to widen or narrow the selected band.

Simplified Definitions

Frequency knob: Select the frequency.

Gain Knob: boost or cut the frequency.

Q Knob: How narrow or wide the group of frequencies is.

Conclucion

An Equalizer is a tool used to shape audio by modifying its frequency content; the EQ achieves that by using filters that allow the cut and boost of frequencies throughout the frequency spectrum division. The most common EQ is a parametric equalizer which is widely used in recording studios. A parametric EQ commonly has bands and filters that allow the sound manipulation.

I hope you have learned something,

Angel De Luna.