Audio Equipment: The Equalizer

This is used to shape a sound source to fit its surroundings. It can mold a sound to imitate other surroundings or add depth or tin to a sound. In music it is used mostly to clear an annoying frequency from a vocal recording, or it is used to separate different sound sources in a song. For instance to separate a main vocal from a background vocal you would probably want the main vocal to have more high frequencies in it, and the background to have more natural or mid frequencies in it.

Basic Parameters
The Equalizer is one of the easiest devices to use. Although it has many knobs and buttons, there are only about six that differentiate.

1. Frequency knob
positions a band to a frequency where you want to adjust. They come in many types of bands. Most common are single, 4-band, and 7-band. This just gives you additional band to use on one unit with out having to stack or use more.
2. Gain knob
after you set the frequency to a curtain position, you can use the gain to add/or subtract decibels to that sound. Each band has its separate gain knob.
3. The Q knob
this is used to adjust the strength of the band. With its shortest or skinniest setting the band only affects the frequency that is selected. With its max or biggest setting the band that is gained will also affect the surrounding frequencies making a bell curve. So if I subtract 3db from 1000hz than 1200hz would go down about 1db.
4. On/In button
the simply applies the band turning it on or bypassed. Other names for this are enable, in, switch, and eq.
5. HPF/LPF
these are bands that make cuts in the waveform. For example a HPF takes the waveform a lets every frequency pass but all the highs (high pass filter). Using the Q knob you can adjust to how much of the high pass can you take out. Visa versa for the LPF (low pass filter). You can also turn it into a notch filter with the button that looks like a upside-down bell. This can take a curtain frequency completely out of a waveform besides just turning it down (notch filter).

Misuses
The most common misuse of the device is that engineers add frequencies to a sound to shape it. Not all sound need to be added. It is just affective if a sound is subtracted and it leaves more room in the song's mix. Subtracting can clear a mix from sounding cloudy.