How To Really Use An Equalizer (EQ)

Ah, the go-to tool for any audio engineer – the Equalizer. Sounds like a Saturday morning cartoon villain doesn’t it? Well, it very well can be one. If you don’t use EQ right, it will completely destroy your mix. You probably heard that sentence a dozen times now, followed by suggestions on what frequencies to cut, which to boost and you probably followed them quite closely. If you did, chances are you are doing something wrong. Before you start giving me a weird look, let me explain:

All that advice you read online about cutting frequencies, boosting them, all those presets, they are all ballpark suggestions that assume you have an ideal audio signal. You don’t. Even with the best room and the best gear, it is unlikely you will have a perfect audio signal!

This is very important to understand and accept. Here is an example:

This is a picture of a vocal track as read by Waves’ Frequency Analyzer. The orange line measures the peak values and is probably what we assume our recorded audio looks like. The yellow line is a real-time display that measures the values at any given point in time – and this is what the audio REALLY looks like. See all those peaks and dips? Now can you imagine using advice like “to give it more presence make a boost with a wide Q around 2KHz”? Sure if you read the peaks it looks fine, but check out what’s happening at a certain moment. There’s already a lot of energy there, so if we boost it further it’s going to end up irritating our ears after a while.

That is exactly what we are trying to avoid and what we really should be doing with EQ – getting rid of nasty, annoying, irritating frequencies.

Now, before I give you actual practical examples, I’m going to have a nerd-moment and offer an explanation of why this happens:

As many of you may know, recording audio is a process of vibrations in the air hitting a microphone and being turned into electricity. These vibrations are frequencies. It’s important to realize that everything and everyone has their own frequency response. Each person’s voice is different, each snare is different, each guitar, microphone, each room too and so on. Nothing is really flat in nature. You never record a pure signal. The source is always contaminated by recording conditions. This is what we are trying to fix with EQ.

“So, how do I do this with my tracks?”, I hear you asking. Simply put – just listen to them. You will, in time if not now, learn to hear when a certain track is annoying your ears. Then you just have to find where that annoyance is coming from, around which frequency, and cut it. This is often done with an EQ sweep. However, if this is new to you and your ears aren’t used to it (it takes years, believe me) then you’ll have trouble hearing which frequencies actually cause problems and which don’t. If that’s the case, a good way to start is by replacing the boosts you’re tempted to do with cuts.

Here’s what I mean:

Are you familiar with that phenomenon where you cut away excess low end in order to get a brighter signal? If not, give it a try right away! If you are, then let me tell you that the same principal applies here. If you cut away problematic frequencies, suddenly the signal becomes much more clear, much more prominent and much more pleasant to listen to. Why? Well, it’s no longer overcrowded, or buried, or being weighed down by values it doesn’t need. Sounds like life doesn’t it? Well, it is.

Here’s a little EQ comparison so you can see what I’m talking about (again, a vocal track):

At first glance, it’s obvious that the above is a nice and lovely preset with a smooth curve while the bottom image is my ugly custom design. Here’s something really fun to take note of. See where the boosts in the preset are? See where my cuts are? It turns out that the vocal track I have was recorded under such conditions that those frequencies are overemphasized to the point of being irritating. If I had used that preset it would’ve completely broken the vocal. (In fact, I did try that preset and I couldn’t listen to song after half a minute because it felt like it was drilling my ears!)

This is where our basic philosophy of “using EQ to bring out the best in our tracks” becomes confusing. The wording implies a boost. We should actually be reading it as “using EQ to take out the worst from our tracks”. Much better. It now implies cuts!

The frequencies I cut here we’re just ear piercing when turned up. First, I noticed that the vocal felt suffocating so I swept the spectrum in search of the culprits. What happened was that when I cut those harsh elements, the areas in between were brought out and the whole vocal not only became more pleasant to listen to but also gained a lot of clean presences. It somehow managed to shine through the whole mix.

I’ve seen audio engineers do this and a lot of them do it much better than me. It takes years and years to really get the hang of. So, don’t be discouraged with your first attempts. Practice, keep applying it whenever you can, break that boosting habit and learn to listen. This is an advanced approach that requires patience, but it does pay off big time in the end.

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You might also like to read: Best Free Equalizer EQ Plugins – a great list with some of the best free EQ plugins for Windows and MAC OS.