General Equalization and Filtering Concept
EQ or an equalizer is a
vital tool in modern audio production.
Therefore, understanding the basic concept of general equalization and
filtering has become very important to mixing engineers. The followings are some basic knowledge of
general equalization and filtering concept that the engineers must know.
An equalizer is a processor that
is designed to change the tonal quality of audio passing through its process. It
operates by using a different numbers of filter circuits that have gain
functions to audio signals of the specific frequency ranges. The positive gain function is referred to
“boost”, and the negative gain function is referred to “cut”.
When we listen to sounds, louder
always sound better, therefore, boosting frequencies will always sound better
than cutting in the short run. However,
in the long run, cutting will create a more natural and cohesive sound.
In addition, our ears are more sensitive
to phase change during boosting and less sensitive when cutting. Therefore, it is very important to apply as
much cutting as possible instead of boosting, and in general, cuttings sound
smoother than boostings. Most of the
time, cutting a specific frequency range will efficiently reduces a frequency
masking and it will make the upper frequencies more apparent.
When boosting or cutting an audio
signal, normally a wider Q or bandwidths are used in boost mode, while a
narrower Q or bandwidths are used in cut mode.
Furthermore, sometimes instead of using a wider Q or bandwidths, using
two narrower Q or bandwidths to distribute the load and focus on specific
frequency ranges work better.
Lastly, when applying equalizer on a whole mix, the fundamental
purpose should be to make sure that
there is no excess or lack of frequency components throughout the frequency
spectrum, and this is called, a “spectral management”. In addition, using the solo function is only
to help you identify some specific frequency component of a sound, therefore, always
check the equalized sound within the mix.
Equalization
always frustrates people, when they cannot feel the differences. Always start with an extreme setting to
identify the specific frequency range, then do the detail touch while listening
the mix. In addition, remember that when
the frequencies are removed, it takes a moment for the brain to adjust. Do not
make an instant judgment.
