19
Using Equalization
One of the most exciting aspects of using a mixer such as the MPL 1502 is the
ability to shape a sound, using a process called equalization. But there are few
areas of sound engineering more misunderstood than equalization, and, just as
good EQ can really help a sound, bad EQ can really hurt it, so read on...
Every naturally occurring sound consists of a broad range of pitches, or
frequencies, combined together in a unique way. This blend is what gives every
sound its distinctive tonal color. The EQ section in a mixer allows you to alter a
sound by boosting or attenuating specific frequency areas. The MPL 1502
provides independent three-band equalization controls for each of its five mono
and five stereo input channels. Each EQ knob is labeled with the maximum
amount of cut or boost provided (± 15 dB in the case of the high and low
frequencies and ± 12 dB in the case of the middle frequency).
We provided these particular frequency areas because they have maximum
impact on musical signals—that’s why they are sometimes known as “sweet
spots.” When an EQ knob is in its center detented position (“0”), it is having no
effect. When it is moved right of center, the particular frequency area is being
boosted; when it is moved left of center, the frequency area is being attenuated.
The high EQ control employs what is known as a shelving curve, where only
frequencies above the specified area are affected. The low and mid frequency
controls employ what is known as a peaking resonant curve (sometimes known
as a bell curve), where frequencies both above and below the specified area are
affected.
In most instances, the best way to approach equalization is to think in terms of
which frequency areas you need to attenuate, as opposed to which ones you
need to boost (boosting a frequency area also has the effect of boosting the
overall signal; too much EQ boost can actually cause overload—with the
accompanying Peak LED warning!). Be aware of the phenomenon of masking,
where loud sounds in one frequency range obscure softer sounds in the same
range; by cutting EQ “notches” in a loud signal, you can actually make room for a
softer one to shine through. And try not to think of EQ as a miracle worker—no
amount of equalization can put a singer in tune or remove the distortion from an
overloaded input signal! The key is to get the signal right in the first place, by
using correct gain structure and mic placement.
Although the specific EQ you will apply to a signal is very much a matter of
personal taste, here are a few general suggestions: Boosting the low frequency
of instruments such as bass drums or bass guitar will add warmth and make the
sound “fatter”; conversely, you may want to attenuate the low frequency compo-
nent of instruments such as cymbals, high-hats, and shakers so as to “thin” them
out. The mid-range control is particularly effective for vocals—attenuating it can
give a vocal performance more of an “FM-radio” feel, while boosting it can help a
vocal cut through dense instrumentation. Be careful not to boost high frequen-
cies too much or you risk adding hiss to the signal, though just a touch can help
add “shimmer” to an acoustic guitar, ride cymbal, or high-hat. Finally, because
the MPL 1502 high EQ utilizes a shelving curve, attenuated settings can be used
to reduce hiss (which is composed almost exclusively of high frequencies).
HIGH
-15
+15
0
MID
-15
+15
0
LOW
-15
+15
0
Summary of Contents for MPL 1502
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