What does EQ do?

EQ can help your audio sound better, correct problems when recording, and even create special and bizare effects on you music!

How can it do all that? First let's take a look at what audio is made of.

When you hear different pitches in music, you are hearing sound waves in different frequencies. A high pitched note comes from high frequency sound waves. Sounds good, huh? ;)

This frequency range goes from 20 hertz to 20 kilohertz (abbreviated Hz & kHz). An average person can hear most of this range, but usually not the extremities. Normally, 40Hz is the low end and 16kHz the high end of a healthy human ear.

When you sing an A note you are making sound waves at the fundemental frequency of 440 Hz. But there are a lot of extra frequencies going there as well, that give your ears extra juice for the sound! I won't go into detail, but they are called overtones.

Overtones give a sound its character. It is what helps your ear distinguish between different sound sources, say a guitar and violin.

Now all this is fine and dandy for a person listening to you in the same room, but when we introduce a microphone to the mix, problems start to occur!

Mics usually color the sound they record. By color, I mean that they can change a few frequencies. A good mic will not color much at all, but some do more than others.

This "coloring" is not all bad, though. High end mics are designed to give a nice smooth sound--they can color your music so it sounds better.

But sometimes this coloring that happens is not what you want. Whether it came from inside the mic or mic placement, things can go wrong.

So when you record several audio tracks and mix them together, you can multiply the problem. You now have something you don't like. How can you fix this?

That's where the whole equalization (fancy for EQ) thing comes into play. With EQ, you can change some frequencies while leaving the rest alone. In this way, you can go in there and tweak the certain spots that need fixing. Then you have a better finished mix!

Now, if you've ever tried this, you know that this is a lot easier said than done, right?!

Here, I'll try to explain roughly what the different frequency ranges do to your sound. I record a lot of a capella music, so you may find a few differences with instrumentation added. (A capella means no instruments)

40Hz is usually as low as most good speakers can make sound at, so it doesn't make sense producing anything below that. The very bottom bass notes are down close to here!

If you have any trouble with your mix clipping, but it doesn't seem too loud, try cutting with EQ around 150-200Hz and lower. If that helps, you had a case of low end build up. That comes from a bunch of tracks with exessive low end sound.

On voice tracks, I've found that you can take away some harsh edge by cutting the 1100-1500Hz area. Don't overuse this, because too much can sound pretty fishy! Wait, do try it. I'll wait. Cut around 1100Hz by 20dB. See how bad (or cool!) it sounds!

The vocals tend to come out a little more if you boost slightly at 5kHz or so. This brings out the upper end of the frequency range. Also try experimenting in the 8-12kHz range. Be gentle though, too much EQ here will show up quickly!

OK, now we discussed some freqency specific EQ things. Let's move on to some higher level stuff again.

Some people will tell you about the "rules" of EQ, what you can and can't do. Get ready, because I'm going to tell you something different!

There are no rules.

What! No rules! How am I going to get anything done?!? Slow down a tad! I say no rules, but I will give you guidlines. You can't really "break" any rules when you're doing this, but if you follow the guidlines you can get somewhere faster.

As you experiment with these EQ guidlines, you will be learning far more than if I just told you what to do. You won't just blindly copy instructions. You will see for yourself what happens, and you will retain it far longer.

So -- rule #1... sorry, guidline #1!

Keep it subtle. Don't do any drastic changes. Unless your dry (unprocessed) audio is very bad, you shouldn't have to do anything major unless you want a wierd effect. If you find yourself doing big changes (like 8dB or more of cut or boost), stop. Come back after a break and see if you still think it needs it.

Guidline #2: When you hear something you don't like in your mix, find what's going wrong. Boost the frequencies in a band of EQ, and "sweep" around to find the frequency that is causing the problem. When you find it, the problem will seem to "jump" out, because you are boosting it. Then, just give it a gentle cut.

After you do this a couple of times, you will learn a tremendous amount about working with EQ!

If something seems lacking in your mix, put a gentle boost on. Do the "sweep" thing again until you find something that works. Alternatively, do a gentle cut and see if there is a spot where you hear a change.

The key is to experiment. Don't give up trying. When you find the problem after a hard search, you will remember that for a long time!

I could go on giving you different tips for different EQ applications, but I think it is better for you to experiment yourself. Go try to take away that boomy sound. When you succeed, you will remember exactly how you EQ'd it!

Here's an article you might want to read for more reference on EQ. Learn more about EQ.