Equalizer (EQ)

In a way, last chapter (about compression) was about the equalizer of volume. The compressor reduces the range from the lowest to highest volume, making the recording a little more equal in terms of power.

What’s the next step after volume? What else can you equalize? Pitch, or frequencies.

But there’s a subtle difference. A reason why we call this the equalizer (or “EQ”). The point of this plugin is not to compress the range of frequencies: to make the recording produce a smaller range of frequencies. That’d be pointless, to reduce every recording to only one pitch :p

No, the name is a leftover from the original purpose of this plugin. Old audio equipment was terrible at reproducing sounds. It often included all sorts of frequencies that shouldn’t be there, while making the crucial frequencies inaudible. As such, the “equalizer” was meant to “equalize” all the different frequencies in volume. To compensate for wild frequencies: those that were too loud or too soft.

In the modern day, we often use it more subtly and for more specific purposes.

I discuss these effects in order of importance and how they are generally applied. Often, you’ll compress a track first (if needed), and then add the EQ (if needed).

How does it work?

Older equalizers had a clear limit on what they could do. They only gave you a few “bands”, a few “ranges of frequencies”, which you could control. Usually, these were,

• Low (LF)
• Low-Mid (LMF)
• Mid (MF)
• High-Mid (HMF)
• High (HF)

You could boost or dampen the volume of each area (individually).

Today, there’s no such limit. You can add as many bands you want. You can boost loads of specific frequencies. Software is unlimited!

But … I don’t recommend that. I think the old limited approach is helpful. It’s easier to make decisions, it simplifies equalizing. And those five bands is really all you need.

When you hear a problem, you don’t think: “man, the 127 Hz on this track is killing me!” You think “hmm that sounds like too many low frequencies, let’s cut some of that”.

Other properties

Okay, so you can pick a frequency and how much you want to change its volume.

As you know by now, however, changes to audio should always happen smoothly. So you’re not changing one frequency, you’re changing a range of frequencies. The plugin draws a smooth curve around the frequency you chose and also changes those near it.

This is controlled by the Q. A higher Q, means a more narrow (and less smooth) range. If you boost the frequency 100 Hz,

• A low Q might also nudge the frequencies 50 Hz-150 Hz in that direction
• While a high Q would only touch the 90 Hz-110 Hz frequencies.

Boosting or cutting frequencies changes the overall volume. Hence, most equalizers have a gain knob. Just like with the compressor, use it to keep the average volume consistent (even after changes).

Play around with the example below. Increase / decrease a frequency range (significantly) and hear what it does with the sound. Try to make the guitar sound fuller, or more “in your face”, or more far away. If you don’t like a part of the sound, try to cut it away.

The equalizer probably has the most knobs and sliders of all effects. Don’t worry if it feels like a lot. Just play with it. Nothing can go wrong, and it trains your ears.

Some EQ plugins allow enabling/disabling your bands quickly. If yours does that, don’t forget to turn on the band you want to use. This is a great way to check if your changes are actually working. Listen to your song with and without the change.

Filters

Most EQ plugins also have shortcut buttons for two crucial types of filters

• High-Pass Filter (or Low Cut)
• Low-Pass Filter (or High Cut)

Their name says it all. The High-Pass filter only lets high frequencies through. The Low-Pass filter only lets low frequencies through.

Most recordings contain rumble in the low end that you don’t need. (It provides nothing for the song, it’s just noise, people barely hear it anyway.) A High-Pass filter sweeps that away.

Similarly, many reverb plugins sound terrible when you feed a full signal into them. Instead, people recommend cutting away the low and high end beforehand, so you only send the crucial midrange frequencies to the reverb.

You can also achieve this by manually doing the setup. The filters are just a very common tool and therefore usually have their own button / shortcut.

When do I use it?

Either to fix issues within a track itself, or to fix issues between tracks.

Within a track

Take my earlier example. A recording of a guitar might have too many low frequencies, or a singer might sing with way too much “sibilance” (high frequencies created on plosives like “s” and “p”). You hear this problem frequency, you cut it away with EQ.

This takes a trained ear. At first, you might only hear that “something is wrong”, but don’t know which exact frequency it is. If so, experiment! Create a big boosting band (so you basically only hear one range of frequencies from this track). Sweep it left to right. When you hear the “problem” getting worse—you’ve found the frequencies responsible for it!

Between tracks

Even if tracks sound great on their own, they might not sound great when combined. If all your recordings have the same focus on midrange frequencies, this will become a major problem when combined. Your whole mix will sound like midrange! The other frequencies are nowhere to be found!

Instead, remember the 3D space of mixing. Each instrument should have its own space. That also means they get their own frequency range in which they shine.

Pink Noise Check (again)

Remember my talk about pink noise in the Volume chapter?

It obviously applies here as well! Most good mixes will resemble a pink noise curve when done. (When you play the whole thing, all tracks combined. Tracks on their own do not necessarily look like it.)

This is an easy, safe check. Place an equalizer on your master track and check the frequencies. If it doesn’t look like pink noise, you want to investigate the frequencies that are missing (or too abundant).

General usage

Earlier I talked about “volume creep”. The same is true for “frequency creep”. Instead of boosting frequencies you hear too little, it’s often better to lower frequencies you hear too much. By doing that, the nice frequencies automatically appear (by contrast). And you never run into that ceiling of “maximum volume on all frequencies” after which you can’t do any more mixing!

The summary? Prefer cutting bad frequencies over boosting good ones.

Practical Tips

I’ll only give one here.

• When you boost frequencies, use a low Q (the boost area is wide and smooth)
• When you cut frequencies, use a high Q (the cut area is narrow and precise)

I have many more tips. So many, in fact, that they didn’t fit in this chapter. It’s a long list of which frequencies matter per instrument and how to handle the different ranges.

I decided to move it to a sort of “appendix”. If you want to read it now, check EQ Cheat Sheet. Otherwise, you’ll find it at the end of the course, after the conclusion.