What even is EQ? [Video]

EQ, or equalization (equalizer), is one of the most useful tools that is in every studio.  Really, it's probably the most helpful tool in all forms of audio work.  Equalizers are how you can shape the tone of a sound that is going through a mixer or in a recording.

EQ, or equalization, is one of the most useful tools that is in every studio.

Yes, it's so important I said it twice!

There are 2 main types of EQ, parametric and graphic.  A parametric EQ is the type of EQ that a mixing board has on each channel.  You can adjust the high frequencies with a knob, the mids with a knob (sometimes more), and the lows with a knob.  They are typically set to a certain frequency range and use a bell curve to change each range.  A bell curve looks like a hill or a dip (depending on if you're adding or removing that frequency) on a chart.  There are some parametric EQs that you can manually set what mid frequencies you adjust.  This is extremely helpful.

The other form of EQ is a graphic EQ.  This is the equalizer that you see in some older stereo systems.  They'll have some number of faders in a row with a frequency listed below them (typically).  You can push each fader up to boost that frequency, or pull the fader down to diminish that frequency.

Which is better to use while recording and mixing?

They both can work, but typically you will want to use a parametric EQ.  The reason for this is that it's faster to adjust, and you get quicker and more musical results.  By more musical results, I mean that it's harder to tell that the tone has been altered, it just sounds right.

Graphic EQs work really well for dialing in the basic sound profile for a room.  It's a bit more exact and has more ways to adjust it.  But as for fine tuning a single track, stem, instrument, vocal (whatever) it's just easier with a parametric EQ.  Not to mention, basically all stock EQ plugins for basically any DAW will be parametric.  That's because it's easier and makes more sense in recording, mixing, and mastering.

What's a Shelf?

When mixing your recordings and looking at the EQ plugin you may notice that the high and low knobs have options.  Like Shelf and bell.  Most of the time, the default setting on the low and the high is shelf (especially if you're using a parametric EQ with more than 3 bands - or adjustments /  knobs). It's called a shelf because whatever you do to that frequency it does to all frequencies either above or below it.  So for the high band, all frequencies above the set frequency with be raised or lowered.  With the low band, all frequencies below the set frequency will be raised or lowered.

Some EQ plugins give you a visual graph, and it literally looks like a shelf when you use this.  Whereas the bell setting gives you that hill or dip look, only adjusting the frequencies near what you're changing.

What about High Pass and Low Pass filters?

These are labeled in two different ways:
  • High Pass / Low Pass
  • Low Cut / High Cut
Either way, they do the same thing.  A High Pass filter is a Low Cut filter.  A Low Pass filter is a High Cut filter.  These are usually adjustable, and they remove all frequencies past what they are set too.  So a High Pass filter will remove all frequencies lower than what it's set to (low cut).  A Low Pass filter will remove all frequencies higher than what it's set to (high cut).

These can be extremely helpful, but they can kill the sound if you're not careful.

A lot of people suggest doing a High Pass (low cut) at about 80Hz on everything but bass and kick drum.  That will clear up space in the mix for these to come through and shine.  But don't do it if it alters the sound (in a negative way) of another track.

As far as the Low Pass (high cut), most people leave it alone unless you need to really get rid of something up there (like a high pitched room noise).  Then again, a lot of people like to do a Low Pass on the main mix between 14K Hz and 16K Hz (K=thousand).  This can help clean up and tighten the high end, and give the recording more of a tube-ish sound.  A lot electronic music producers (like EDM producers) music will leave as much high head room as possible and not use this filter.

If something doesn't sound quite right, how can I use EQ to shape the sound?

Here's the bread and butter of EQ and the most helpful advice I can give you - use a subtractive EQ technique.  What that means is use EQ to pull out more bad frequencies than to push up good frequencies.  Remember, the microphone is the first part of EQ.  Try to get the best natural recording you can using different mic placing techniques.  Then use the EQ to pull out the parts that are making the track not sound as good as it can.  You may end up adding a little bit here or there too, but pull more out than you add in each track.

The second most helpful advice I can give you is this - a little bit goes a long way.  If you're recording has 2 guitars, 3 vocal tracks, drums, bass, keys.... a little pull off of each track adds up in the end.  You don't need to pull 10db  out of a frequency range on the voice (if so you might want to re-record that one using a different mic placement), and you don't need to add 10db to a frequency range either.  3db goes a long way - but use your ears, not the chart.

Most importantly, use your ears.  If it sounds right, it is right. Right?  Remember, music is subjective.  Make something you love and love making it!