When it comes to equalizing your tracks, a parametric EQ is one of the most versatile equalizers that you can use. That’s because, it offers the flexibility to make vastly different types of alterations to the sound of a signal.
With a parametric EQ, you can make very subtle changes to the frequency spectrum, but you can also make extreme ones as well. Similarly, you can pinpoint very specific frequencies to equalize, but you can also make broad changes to large groups of frequencies too. Because of this, parametric equalizers enable you to make the exact changes to the way an instrument sounds that your mix needs. In this article, I’ll explain what a parametric EQ does and how to use one.
What is a parametric EQ:
A parametric EQ allows you to make a cut or a boost to the frequency spectrum. The frequency response curve that a parametric EQ creates resembles the shape of a bell. These bell shaped cuts and boosts can be made to your desired gain amount. You can also select the frequency at which the boost or cut is made. For example, here you can see a boost of 6dB at 1kHz:
Whereas here, you can see a cut of -9dB at 300Hz:
Where a parametric EQ comes in really handy is that, in addition to being able to specify your desired frequency and gain amount, a parametric EQ also allows you to control the width of the cut or boost that you’re making. For example, here you can see a very narrow boost of 5dB at 10kHz:
Whereas here, you can see a very wide cut of -8db at 500Hz:
Controlling a parametric EQ:
To achieve these different kinds of equalization, you must control three separate parameters. Those parameters are: gain, center frequency and bandwidth:
Gain: The gain parameter on a parametric equalizer allows you to control the amount of boost or cut that you are applying.
Center Frequency: The center frequency refers to the frequency which resides at the very center of the bell shaped boost or cut that you are making.
Bandwidth: Bandwidth refers to how narrow or wide your boost or cut is. Bandwidth is usually controlled by a ‘Q’ setting, which stands for ‘quality factor’. The higher the value of the Q setting, the narrower the bandwidth will be. Similarly, the lower the Q value, the wider the bandwidth will be.
Fully-parametric vs semi-parametric:
A parametric EQ which allows you to control all three of these parameters is known as ‘fully-parametric’. Some equalizers allow you to alter only the gain and the frequency of the equalizer, and have a fixed bandwidth / Q setting. These are referred to as ‘semi-parametric’ or ‘sweepable’ equalizers.
Why use a parametric EQ?
Parametric equalizers offer an unparalleled level of flexibility over the kind of equalization you create. By allowing you to take control over the equalizer’s gain, center frequency and bandwidth parameters, you are able to make precise EQ alterations to suit the needs of your mix. You can make changes to large portions of the frequency spectrum to change the overall sound of a signal. But you can also make very specific, surgical alterations to really fine tune your sound as well. The ability to make such varied alterations makes a parametric equalizer an extremely versatile EQ to use.
Do you use a parametric EQ when you mix your songs? If so, what sort of things do you use it for? Leave your ideas in the comment section below.