My goal here is to keep this simple but helpful so, let me start with definitions:
An Equalizer is a piece of equipment (physical or virtualized) which allows an audio engineer to increase or decrease (boost or cut) specific frequencies or frequency ranges along the entire frequency spectrum.
Equalization, “to EQ”, or “EQ-ing” is what audio engineers call the process of increasing or decreasing sound frequencies or frequency ranges.
Important: This is a very simplified take on EQ-ing. There are many aspects to the art of audio Equalization that we are not going to go over in this article. That’s because I cannot teach you how to become an audio engineer in a Medium post, and if I were to try I would fail miserably. You learn how to EQ well by EQ-ing poorly — you have to suck at it before you can be good at it. Some of the things I will say here are incredibly broad, even the frequencies in some of the examples, I’m doing this on purpose. I’m introducing you to Equalization, not teaching it to you. One day you will be so good at this you will come back to this article and be like
“Wow, he really was being super non-specific and a lot of this was wrong and I know that because I’m so super good at this now.”
And when that day comes, young Grasshopper, you can make the check out to CASH and drop it off at my studio, because it will be this basic article that gets you comfortable enough to start screwing around with EQ.
So, with that in mind, my intent here is to explain what parts of the voice correspond to what frequencies so that you can recognize them when you hear them and so you can get started EQ-ing today and work towards becoming good.
There’s only one way to do this, and that’s frequency range by frequency range so there are going to be a lot of embedded audio clips in this post — prepare your earballs.
Physical vs Virtual
Some Equalizers, as I said at the outset, are physical boards. These are the big expensive looking boards you see in professional studios with vertical sliders and twisty dials all over the place, they look like this
It is more likely, however, that you are using a DAW (a Digital Audio Workstation like Audacity, Adobe Audition, or Pro Tools) and would have a virtualized Equalizier in the form of a VST (aka Virtual Studio Technology, aka a plug-in) that looked something more like this.
Those vertical sliders on the physical equalizer are the same as the 1,3,5, and 7 numbers you see on the virtual equalizer (and you can have more numbers, err… virtual sliders…, these are just the ones I had enabled when I took the screenshot).
Sliding a physical slider UP, boosts a frequency range. Sliding a physical slider DOWN, cuts a frequency range. The same is true of dragging those little numbers up or down.
The reason most podcasters don’t use a physical equalizer is because physical equalizers don’t show you what you’re doing in a way that’s easy to comprehend if you don’t understand sound and most podcasters don’t understand sound the way an audio engineer or producer understands sound. Virtualized Equalizers are visually comprehensive, as you’ll see in a moment, and that makes it easier to understand what you’re doing.
One other thing before we start: The numbers running up the right-hand-side are measures of dB (which is a measure of loudness, when you increase dB you make things louder, when you decrease dB you make things less loud). The numbers along the top are indicators of Hertz (Hz) and Kilohertz (KHz) — those are your frequencies. Put those things together: when you boost a frequency range you increase its loudness, so you can hear it more easily. When you cut it you do the opposite.
Remember, you’re learning and you should be keeping it basic until you get comfortable.
Be sure to listen to the audio files in this article WITH HEADPHONES.
The Raw Audio
Here’s the audio file we’ll be working with with absolutely no modification made to it.
And here’s a picture of what that audio looks like (same photo from above)
The Low End Roll-off
Low, droning frequencies are all around you. They can be caused by ground loops, poorly shielded audio cables, power adapters in a nearby outlet, refrigerators, road noise, the list goes on. Luckily, this phenomenon, referred to as “Machine Hum” or “60Hz” hum, happens at 60Hz and lower, which is well-below the typical vocal frequency of men (85–180hz) and women (165–255hz). The first thing you want to do during the EQ-ing process, is roll-off everything below 60Hz. In your Equalizer it will look something like this
and the difference sounds like
You may not notice much of anything there, and that’s okay, sometimes you need it and sometimes you don’t, in the case of this audio I didn’t need it that much (our environment is mostly free of that low frequency stuff) and you may not be able to hear the difference. Either way, it’s a good practice to do this with all your vocal tracks.
100–200Hz Boost and Cut
This range is where your bass lives, this is where radio hosts have the deep recognizable “broadcaster” quality and it is usually boosted but, as is the case with myself, you may find that the vocal is already pretty deep and you’re not looking for the warmth of that traditional broadcaster voice — in which case you would cut it. Here’s what boosting it might look like
And sound like
Here’s what cutting it looks like
and sounds like
The opposite of bassy, yeah?
400–1000Hz Boost and Cut
The next range is where the muddy mumble bee part of your voice is. You’ll understand what I mean when you hear it boosted — here’s what it looks like and sounds like.
You get what I mean now by “muddy”? It gets groggy and mumbly in this range — it’s the womp womp of Charlie Brown’s teacher.
1000–4000Hz Boost and Cut
This is the range where things get nasally, there’s also a chance your sibilants (the sound of harsh consonants, S’s most commonly) live at the higher end of this range. Here’s the boost
and here’s the cut
6000–14000Hz Boost and Cut
This is the airy part of your voice, a lot of clarity can come by boosting within this range. Your sibilants are also likely to exist in this range (especially if you’re a woman — men are usually around 5000–6000 women are closer to 7000–9000 in my experience).
Here’s the boost
and the cut
Let’s put it all together
Okay so clearly the boosts and cuts above are extreme to illustrate their effect on the audio — you normally wouldn’t boost or cut frequency ranges to this extreme… probably never, in fact. Here’s what it would look and sound like if I was EQ-ing this audio for a client
Compare that to the original
Pretty amazing, right? That’s just the EQ changes.
Here’s what it would sound like after we did all the other things to it we would do for a client
As you can see, Equalization has a huge effect on your audio and now that you have a basic idea of what that effect sounds like as well as how to operate your own virtualized equalizer, you can go and start playing around with your own recording audio.
As always, if you have questions, ask. Advice is free.