12
About Equalization
The E62i, E31i and E30i give you fine control over shaping 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 range of frequencies that can be heard by humans is sometimes called
the audible range, and it includes frequencies from as low as 20 Hz (that is, 20 wavecycles
per second) to those as high as 20 kHz (that is, 20,000 wavecycles per second).
The E62i and E31i provides a set of high-quality filters that divide the audible range into
31 1/3 octave frequency areas, centered at 20 Hz, 25 Hz, 31.5 Hz, 40 Hz, 50 Hz, 63 Hz,
80 Hz, 100 Hz, 125 Hz, 160 Hz, 200 Hz, 250 Hz, 315 Hz, 400 Hz, 500 Hz, 630 Hz, 800 Hz,
1 kHz, 1.25 kHz, 1.6 kHz, 2 kHz, 2.5 kHz, 3.15 kHz, 4 kHz, 5 kHz, 6.3 kHz, 8 kHz, 10 kHz,
12.5 kHz, 16 kHz, and 20 kHz. The E30i uses the same high-quality filters, instead dividing
the audible range into 15 2/3 octave frequency areas, centered at 25 Hz, 40 Hz, 63 Hz,
100 Hz, 160 Hz, 250 Hz, 400 Hz, 630 Hz, 1 kHz, 1.6 kHz, 2.5 kHz, 4 kHz, 6.3 kHz, 10 kHz,
and 16 kHz. In all three models, “Constant Q” circuitry ensures that the bandwidth of each
of these frequency areas stays the same even when approaching maximum boost or
attenuation resulting in greatly reduced phase shifting and intermodulation distortion.
Each frequency area can be cut or boosted by as much as 12 dB. The E62i and E31i
models also provide ±12 dB switches; when these switches are off (in the up position),
each frequency area is cut or boosted by just 6 dB, giving you finer control and allowing
you to construct gentler frequency curves.
In addition, the E62i and E31i models provide a Cut Only mode. If the Cut Only switch(es)
on the front panel are off (in their up position), then when an Equalizer slider is in its center
detented “0” position, it is having no effect; when it is moved up, the particular frequency
area is being boosted; when it is moved down, the frequency area is being attenuated
(cut). However, if the Cut Only switch(es) on the front panel are on (in their down position),
the blue labels on the front panel indicate the action of moving an Equalizer slider; when it
is at its maximum (fully up) position, it is having no effect; when it is moved down, the
frequency area is attenuated (cut). In this circumstance, the center detented “0” position
represents a cut of -6 dB (if the ±12 dB switch is out) or -12 dB (if the ±12 dB switch is in),
and the minimum position represents a cut of -12 dB (if the ±12 dB switch is out) or a
whopping -24 dB (if the ±12 dB switch is in).
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 overload-
ed input signal! The key is to get the signal right in the first place, by using correct gain
structure and mic placement.
ENGLISH
