Instruction Manual

13
B1-GRQ-2-OpGuide-v1-060519.pmd
SECTION SIX: USING GRAPHI-Q2 CONTROLS
6.2.2. Linking Channel Controls (Two-channel Units)
Two channel Graphi-Q2 units offer a useful and unique feature for linking channel controls. Pulling all the
A channel EQ sliders to the bottom defeats these controls, and applies the B channel settings to the A
channel as well. Now the B channel sliders act as master control for both channels. This applies not only
to the graphic EQ controls, but to controls for the compressor, high and low cut filters, and output gain.
Delay, bypass, and FBX filter controls will remain channel specific (in other words, to bypass the graphic
EQ for the A, you must press “Bypass” for channel A).
6.2.3. The Tweek-n-Peek Feature (Front Panel Models only)
If you’ve been experimenting with the controls on your Graphi-Q2
front panel, you’ve probably already figured out Sabine’s new
“Tweek-n-Peek” feature. If you’ve ever grabbed a graphic EQ
fader, moved it, and wondered what the “real” setting was, your
prayers have been answered. Tweek-n-Peek shows you the
value of every control on the front panel while you adjust them. As
you move a compressor knob or EQ slider, the value of the setting
for that control will appear in the LED screen that normally displays
the digital delay time. After two seconds of no further adjustment,
the display will revert to the digital delay setting. This means you
can adjust all your controls to a precise, repeatable setting, not
just to a vague knob or fader position. The accuracy of your
settings for all the parameters of your Graphi-Q2 is thus signifi-
cantly improved. The resolution of front panel graphic EQ fader
settings is ½ dB when the range of boost/cut is +6 dB, or 1 dB when
the range of boost/cut is +12 dB. (When using the remote
software to control the EQ faders the resolution is always ½ dB,
regardless of range.)
6.3. HIGH CUT/LOW CUT FILTERS
6.3.1. Front Panel Control
These controls are located immediately to the right of the graphic EQ sliders. For the LOW
CUT FILTER, the Graphi-Q2 will attenuate frequencies at and below your knob setting with
a slope of 12 dB per octave. For the HIGH CUT FILTER, frequencies at and above the knob
setting will be attenuated 12 dB per octave. The extreme counterclockwise knob position
of the LOW CUT FILTER and the extreme clockwise position of the HIGH CUT FILTER turn
the filters off. The range of the HIGH CUT FILTER extends from a starting point of 3 KHz
to 20 KHz. The range of the LOW CUT FILTER extends from 20 Hz at the bottom to 1 KHz
at the top. The frequency chosen is the point at which attenuation of the filter reaches 3 dB.
In other words, the filter roll-off actually begins just above (for low cut filter) or below (for high
cut) the chosen frequency.
6.4. FEEDBACK CONTROL AND PARAMETRIC EQUALIZATION
Operation of the FBX Feedback Exterminator section of the front panel of your Graphi-Q2 is simple, but
may require a brief explanation for those of you unfamiliar with Sabine FBX products and/or terminology.
Let’s begin by defining a few key terms.
6.4.1. Glossary of Terms
• FEEDBACK describes what happens when a loudspeaker disperses sound back into an amplified
microphone, at a level sufficient to allow one or more frequencies to ring out of control. Feedback can
occur at any frequency, but is especially painful at mid to high frequencies. The specific frequencies
that feedback in a particular situation depend on the acoustics of the environment, the placement of
the microphone(s) and speaker(s), the response characteristics of the sound system components, and
the volume of amplification. Anyone who has operated a sound system or attended a conference or
a concert is familiar with feedback and its unpleasant consequences!
•A PARAMETRIC EQUALIZER allows the user to precisely specify three critical values that
determine an equalizer’s characteristics: the center frequency of the EQ band that is boosted or cut
(measured in Hertz), the amount of boost or cut imposed at the center point (measured in dB), and
the width of the bell-curve shaped frequency band that is affected (typically measured in octaves).