This is a small chapter regarding the equalizer. For some people, equalizer is something on their sound system, two knobs, one for bass and one for treble. For others (like me) this is a very simple thing that quickly get very complex in it’s simple nature.
The equalizer comes in many different forms, from simple two, three of four knobs on a mixerboard channel to it’s own stack with multiple bands for each channel. But no matter how it looks, the usage is the same.
The whole point with an equalizer is to cut or boost the audiosignal in a specific Hertz (Hz) range. This means that if you use an Equalizer knob marked 3kHz (= 3000 Hz), you will affect the audio signal in (and around) 3kHz. If you turn it up (+) you will boost the signal which will make that part of the signal louder. If you turn it down (-) you will cut the signal which will make that part of the signal more quiet.
In general all Equalizers affect the specified value (Hz) and a range above and below that value. And if there are two knobs, they are usually for treble (high frequensies) and bass (low frequensies).
Then there can be three, and then it is usually for mid-range usage. Every now and then you’ll find four knobs, and the fourth would control the value of the mid-range, changing if from darker to brighter area of control.
For my personal tast, I prefer to cut out content rather than boosting content. But that is my personal preferance. I usually cut out unwanted frequensies from the signal.
A good thing can be to cut out low frequensies from a recorded signal (or even better, use it while recording, so those frequensies is not polluting your recording in the first place) like buzz, traffic noice etc. And on the opposite end of the scale there is the high frequensies from ventilations or draft in windows, that you can filter out using the Equalizer.
Should you have a multiband equalizer each controller will affect a smaller range, and as so, you can isolate only the frequensies that you want to use from each specific signal. But this is rather advanced stuff and nothing I recommend doing from the start.
I hope this small section has given you a better understanding of what the Equalizer does, and I urge you to play with it. It is a powerful tool, but it can also easily and quick turn your signal to a terrible signal. Play around and listen to what your equalizer does to your signal, try to use it in a wise way.