Equalizers (EQ) are one of the core elements of mixing. I can mix a song with two or three compressors, but please give me at least one EQ for each channel.
EQs mainly help to manage the balance of frequencies of the song. Let's see its main parameters, and then some practical advice.
Type Of Equalizers:
There are three common types of equalizers: parametric, semi-parametric, and graphic.
The main difference between these EQs is the number of parameters available.
Parametric: frequency, boost/cut, Q
Semi-parametric: frequency, boost/cut
Graphic: boost/cut (they have fixed frequencies)
Frequency — This is the point in the frequency spectrum at which the EQ is applied.
Boost/Cut — The amount of gain (boost) or reduction (cut) applied at a given frequency.
Q (or bell) — Q stands for “quality factor.” This is the number of frequencies next to the selected one that will be affected by the boost or the cut.
EQ Practical Advice:
If you find yourself over-EQing an instrument or experimenting with an EQ over and over, your ears are probably tired. Take a break.
Do not EQ in solo unless you're trying to fix a specific problem.
You can’t EQ frequencies that are not there.
Use a narrow Q when cutting and a broader Q when boosting.
Always match the volume pre/post EQ, so you don’t get fooled by the difference in volume when comparing the processed and non-processed sound.
Don’t boost all the instruments on the same frequencies but try to choose different frequencies to reduce the masking effect.
Use digital EQs to cut and analog emulations to boost.