PreSonus AudioBox 1818VSL - Manual (Page 81)

75
Owner’s Manual
Ov
er
view
Hook
up
Connec
ting
to
a
Comput
er
Tut
orials
Technical Informa
tion
Tr
oubleshooting and
W
arr
an
ty
Sof
tw
ar
e: V
irtual
StudioLiv
e
AB1818VSL Remot
e,
and S
tudio O
ne Ar
tist
Tutorials 5
Tut
orialsl
Equalizers 5.3
A broad bandwidth accentuates or attenuates a larger band of frequencies. The
broad and narrow bandwidths (high and low Q) are usually used in conjunction
with one another to achieve the desired effect. Let’s look at our kick drum again.
We have a kick drum that has a great, big, low-end sound centered around 100
Hz and an attack hitting almost dead-on at 4 kHz. In this example, you would
use a broad bandwidth in the low frequency band, centered at 100 Hz, and a
narrow bandwidth boosted at 4 kHz. In this way you are accentuating the best
and downplaying everything else this particular kick drum has to offer.
Shelving EQ
A shelving EQ attenuates or boost frequencies above or below a specified cutoff
point. Shelving equalizers come in two different varieties: high-pass and low-pass.
Low-pass shelving filters pass all frequencies below the specified
cutoff frequency while attenuating all the frequencies above it. A
high-pass filter does the opposite: passing all frequencies above the
specified cut-off frequency while attenuating everything below.
Graphic EQ
A graphic EQ is a multiband equalizer that uses sliders to adjust the
amplitude for each frequency band. It gets its name from the positions
of the sliders, which graphically display the resulting frequency-
response curve. The center frequency and bandwidth are fixed; the
level (amplitude) for each band is the only adjustable parameter.
Graphic EQs are generally used to fine-tune the overall mix for a particular
room. For instance, if you are mixing in a “dead” room, you may want to boost
high frequencies and roll off some of the lows. If you are mixing in a “live”
room, you might need to lower the high-midrange and highest frequencies. In
general, you should not make drastic amplitude adjustments to any particular
frequency bands. Instead, make smaller, incremental adjustments over a wider
spectrum to round out your final mix. To assist you with these adjustments, here
is an overview of which frequencies affect different sound characteristics:
Sub-Bass (16 Hz to 60 Hz). The lowest of these bass frequencies are felt, rather
than heard, as with freeway rumbling or an earthquake. These frequencies give
your mix a sense of power even when they only occur occasionally. However,
overemphasizing frequencies in this range will result in a muddy mix.
Bass (60 Hz to 250 Hz). Because this range contains the fundamental notes
of the rhythm section, any EQ changes will affect the balance of your mix,
making it fat or thin. Too much emphasis will make for a boomy mix.
Low Mids (250 Hz to 2 kHz). In general, you will want to emphasize the lower
portion of this range and deemphasize the upper portion. Boosting the range
from 250 Hz to 500 Hz will accent ambience in the studio and will add clarity to
bass and lower frequency instruments. The range between 500 Hz and 2 kHz
can make midrange instruments (guitar, snare, saxophone, etc.) “honky,” and too
much boost between 1 kHz and 2 kHz can make your mix sound thin or “tinny.”
High Mids (2 kHz to 4 kHz). The attack portion of percussive
and rhythm instruments occurs in this range. High mids are also
responsible for the projection of midrange instruments.