And the third drawback (and a very important one) is that even if adjacent sliders are close to each other, it’s impossible to make the spectrum change perfectly smoothly. This characteristic of graphic equalizers causes contortions in the sound. They might not be perceptible in the live performances, but can be very significant during recording.
That’s why professional mixing studio usually avoid using graphic equalizers and choose parametric ones, which are more flexible and precise.
Unlike graphic equalizers, parametric ones don’t have so many equalization bands. However, due to the ability of precise frequency localization, they have become a number one tool for mixing songs. Parametric equalizers usually have from one to four bands. Sometimes these bands are tied to a certain range and the band frequency can only be set in this range, but often all bands can be adjusted within full range. The name “parametric equalizers” was given to these devices because they have entirely modifiable equalization parameters. In the right hands, these tools can give a mixing engineer a great advantage in creating a musical pattern.
Imagine that you need to pack two sounds with a similar spectrum in one mix and ensure that both of them are audible. In this case, reasonable equalization of each instrument will provide a separate space in the song for both of them.
Some frequency conflicts are solved by turning on High-pass and Low-pass filters, which also relates to equalization.
In some cases, an equalizer helps to remove timbral weakness of a voice or an instrument and adjust the influence of the room, standing waves or resonances on the sound.
All told, the equalizer has many usages in sound mixing studios. As any other instrument (yes, in relation to music the equalizer is exactly a musical instrument) it requires some skills and experience to work with to achiee result similar to our before after mixing mastering demos.