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EQ

EQ is probably the first tool you will reach out for when a certain track needs a little tonal shaping. What the EQ does is that it cuts or boost certain frequencies. The two main types of EQ´s are Parametric EQ and Graphical EQ. They pretty much do the same, but in different ways, and are optimized for different purposes.

A graphical EQ in the traditional hardware form has a number of fixed bands which you can cut or boost. As the bands are fixed there is often a high number of bands. Below you can see the DBX 231 Graphic EQ. It is a stereo EQ with 2 x 31 bands. These EQ´s are often used as a "Master EQ" in a live rig rather than as a more surgical studio machine.

A parametric EQ has fewer bands, often 3-5, but these bands are far more flexible. This means that you can specify excactly which frequency range you want to shape, which will let you make more surgical adjustments. The "Q" factor defines how wide or how narrow a frequency range you cut or boost. Here you can see the 1st channel of the Avalon AD2055 parametric stereo EQ.

Tip: A general EQ "Rule of Thumb" is that when you boost it´s best to use a wide frequency range. More surgical adjustments is most suitable when cutting. Below you can see an example showing the EQ plug-in in Logic.

A third kind of EQ is the socalled Match EQ or Fingerprint EQ, which analyzes the EQ profile of one audio source and applies this profile to another audio source. Often these Fingerprint based EQ´s come with a bunch of EQ profile presets, but you can use your own source as well. Here you can see screenshots of TC Electronic´s "Assimilator" EQ for Powercore systems.

Here you can see a chart showing which frequency ranges different instruments covers. Click on the image to zoom.

Links to EQ related articles:

Equal Opportunities (Sound on Sound Magazine, February 1997)

Using Equalisation (Sound on Sound Magazine, August 2001)

The Equalization primer (www.recordingwebsite.com)

Equalization - Sound Mixing (www.macmusic.com)