The EQ Explained

The Equalizer, or EQ, is essentially a representation of all of the frequencies that make up an audio piece. Understanding EQ is crucial to understand not just the anatomy of music, but how to make it yourself. In a song, each instrument and sound is designed to take up a certain place in the EQ, and they all collaborate to eventually conquer and fill as many of the frequencies as possible.

I like to think of the EQ with 3 main segments: basses, mids, and trebles.

Trebles are the higher frequencies on the right that are mostly reserved for vocals. With the exception of a few sounds--perhaps drums like hi-hats and cymbals--, it is best to scarcely populate these frequencies when making instrumentals, leaving room for the vocalist.

The basses are the lower, deeper sounds in the EQ. Here, you’ll find your kicks, 808s, and other acoustic bass sounds. Many producers agree that bases are slightly more difficult to manipulate than other frequencies because a lot of the time, they aren’t represented well enough in speakers. We’ll look into that a bit later.

Middle-frequencies, which are often referred to as “mids”, lie between bases and trebles. Mids are where the bulk of instruments reside--pianos, guitars, claps, and snares are just a few examples.

Middle-frequencies are, in my eyes, the most versatile frequencies. Since mids are the strongest frequencies in consumer speakers like phones, tablets, and laptops, they are critical to sound design. This lack of strong bases in common devices forces producers to occasionally push bass sounds into the lower area of the mids and boost those frequencies. This effectively boosts the closest audible frequencies to the actual bass sound.

When adjusting the frequencies in a piece, it is imperative that each sound has its own purpose--and a great way to do that is filters.

A high-pass filter is designed to only let the higher frequencies pass through. This makes sure the higher frequency sounds do not interfere with any of the lower frequency sounds.

For example, if a song has a certain piano melody that is very full--it has a vast array of frequencies--a high pass filter would be used to ensure the piano’s lower frequencies would not clash with a sub-bass or 808--sounds that are designed to host lower frequencies.

Low-pass filters achieve a similar goal and are designed to only let the lower frequencies pass through.

Knowledge of the EQ is crucial to any musical composition. Regardless of genre, understanding EQ and the individualized purpose of each sound can drastically change the projection of a track.