The Art of EQ – Overview

Sometimes your sound just needs a little something. Here’s an overview on how to use your channel strip equalizer to make the most of your sound.

You’ll probably recognize the picture below as the equalizer section of your channel strip. But rather than blindly spinning knobs, you need to know how each control operates before you apply this during a worship service.First note the IN/OUT switch at the top of the picture. Also called ON/OFF in many cases, not every console has one of these, but when they do this switch must be turned “IN or ON” before the equalizer will do anything at all. Also, be careful to have all the other knobs centered (or normalized) before turning this switch on, as that’s a sure way to cause feedback problems.

Next, note there are four dark gray knobs labeled HIGH, HIGH MID, LOW MID, and LOW. These knobs each control one of four frequency bands, typically the HIGH knob will control frequencies around 12 kHz (12,000 Hz), the LOW knob will control frequencies around 80 Hz, and the MID knobs will be sweepable frequencies. More on this later.

Also, these same HIGH, HIGH MID, LOW MID, and LOW knobs are marked with a U at the top and a -15 and +15 labels at the counterclockwise and clockwise extremes. U stands for Unity also marked as 0 (zero) on many consoles. What this U or 0 means is to do “nothing.” What ever goes into the strip in the frequency area will remain unchanged. Turning the control clockwise to the first line will boost that frequency area by 3 dB (decibels), the next line is 6 dB, 9 dB, 12 dB, and 15 dB of boost as finally marked. Turning the knob to the left (counterclockwise) will result in the opposite effect, where those frequencies are reduced (or cut) by -3, -6, -9, -12, or -15 decibels. Of course, this is a continuous control, so you can select 4.63 decibels if you can hear it…. but the markings are in 3-dB steps.

Also, note that the HIGH MID (level) knob has another control associated with it, the FREQ knob that’s sweepable from 400 Hz to 8 kHz. This allows you to sweep the frequency band the HIGH-MID know will affect. So, with the FREQ control set at 2 K in the picture to the left, the HIGH-MID control will boost or cut the frequencies centered around 2 kHz (2,000 Hz). So if you have the HIGH-MID control centered at U, you won’t hear any effect by turning the FREQ control. However, if you boost the level by say, 6 dB on the HIGH-MID control, you’ll be able to hear the frequency sweep as you change the FREQ knob. The LOW-MID section duplicates this function except for the frequency range of 100 Hz to 2 kHz.

The best way to learn what these controls really sound like is to simply play a CD track through the channel and sweep the frequencies around a bit. You’ll quickly hear what 400 Hz sounds like and why 3 kHz is called “presence.”  Be bold and make some noise when nobody else is in the room. Then you’ll have more confidence the next time during a service when you hear an instrument “booming” or in need of some “bite.”

To correlate these frequencies with the real world there’s a frequency chart included below that shows a piano keyboard and how it relates to both numerical frequencies and various voices and instruments. Get to know which instruments can be affected by certain frequency ranges. After a while you’ll be able to hear a problem frequency and relate a number to it. Then just set the FREQ knob in the general area, apply a little boost or cut as desired and sweep the FREQ knob until you’re exactly tuned in. Then you’re REALLY mixing like a pro.


Copyright Mike Sokol 2015 – All Rights Reserved

Leave a Reply

Your email address will not be published. Required fields are marked *