How to use a graphic equalizer (EQ)

By Andrew Kim, on October 18, 2011

This blog post will teach you the basic theory behind using an equalizer to tune and improve the sound you get from music, games, and movies on your PC.

First of all, what IS an equalizer?

An equalizer is an electronic circuit that allows you to selectively amplify an audio signal based on various frequency bands. This is typically accomplished using independent volume controls for each frequenmcy band. The simplest equalizer (or EQ, as it is also known) would be a "bass" and "treble" knob on a basic stereo system. Turning up the Bass will make the lower frequencies louder, while turning up the treble will make the higher ones louder.

In high-end audio reproduction, you need a lot more than just two knobs, as demonstrated by the production soundboard below!


Audio Soundboard



A similar function can be accomplished on most personal computers. However, instead of having a row of physical sliders like those on the soundboard, the PC uses software to control this function. As you can see from the screenshot below, many PC equalizers are designed to look a lot like their soundboard counterparts.


Equalizer, flat EQ


This screenshot (above) of the equalizer from Corsair's Vengeance™ 1500 Gaming Headset controller software shows a "Flat EQ" setup, where the amplification level for each frequence is exactly the same. But how do we adjust these settings?



This second equalizer screenshot shows an equalizer with adjusted settings. In this particular case, the lower (bass) frequencies have been boosted, while frequencies in the 8K Hz band have been attenuated. Since all these sliders can be adjusted, it is possible to vary the sound fairly dramatically.

An EQ is very intuitive. Each slider is responsible for a range of frequencies, and as you increase the number of sliders the sound can be more finely tuned. The higher you raise a slider, the more gain you will get. In other words, the volume increases at that frequency. The most common usage of the EQ is for “bass boost”. Many people love the feeling of that rumbling low bass, pounding away while you bob your head to the beat.

But an EQ can be temperamental, and carries some fine print. Moving an EQ band too much and at the wrong places can negatively affect the quality of the sound. All sound output devices have different characteristics, and the more you understand those characteristics, the more fully and effectively you can utilize the EQ to optimize the sound of your headphones or speakers. If you can manage to achieve the sound you want by lowering some sliders rather than raising the other sliders, this is the way you want to go.

Playing around with the EQ is a great way to maximize the enjoyment you get our of your speakers or headphones. Take some time to play around with the equalizer on your PC to obtain the sound that is right for you. Simply raise and lower sliders, remembering a little bit can go a long way! Then, when you like the quality of the sound, simply raise the general volume up to match how loud you would like it to be.