Behringer FBQ6200/FBQ3102/FBQ1502 - Manual (Page 8)

8 ULTRAGRAPH PRO FBQ6200/FBQ3102/FBQ1502 User Manual
3.1 Master equalizer in sound
reinforcement systems
This diagram shows a typical set-up with the ULTRAGRAPH PRO models
(see fig. 3.1).
To achieve optimal results, you should pay attention to several issues:
Before you start correcting the frequency response of a setup, it is advisable to
first let the music and other sound sources run “uncorrected”, as this is something
that has proven itself in practice. If distortion occurs, such overdriving is the first
issue to be overcome in your setup. Loudspeaker location is also very important.
No equalizer in this world can significantly correct the dull sound created through
reflexion of wall structures and ceilings. Often, very dramatic improvements can
be made by simply placing and aligning speakers correctly.
If you are using an active multi-way system you should take some run-time and
phase correction measures before you work with the ULTRAGRAPH PRO (our
crossover network SUPER-X PRO CX3400 provides all the necessary tools with
its variable split frequencies, phase reverse switches and electronic run-time
correction facility). Only after making these preliminary adjustments should you
start implementing them on your ULTRAGRAPH PRO.
Disturbing noise (e. g. mains-induced hum) as well as narrow-band resonances
should first be tackled by using the ULTRAGRAPH PRO (also see ch. 3.2.1).
You should definitely perform all these adjustments before modifying the
overall sound.
Now you have a basic setup and now it’s time to start fine-tuning your sound.
Some ground rules:
A linear response curve is not ideal for every application. For example,
when dealing with the spoken word, intelligibility is what is most important.
Therefore, the transmission curve should drop off in the bass segment of the
signal because otherwise only interference is transmitted.
In general, extremely low and high frequencies are transmitted with much
lower amplitudes. There is no sense in “forcing” a small full-range speaker to
reproduce frequencies below 50 Hz; apart from a need for higher power reserves,
speaker damage will be the most likely result.
◊ Always respect the physical limitations of your system.
After setting up your system as precisely as possible to the desired transmission
curve, walk around the venue in order to get an impression of what your signal
sounds like in different locations. Do not forget to take regular breaks while you
do this, and also try to use various program sources to truly develop a feeling for
what your system really sounds like and how the venue carries the sound.
◊ Setting up your equalizer well takes a lot of time and patience! If you
notice that only extreme settings on your equalizer create a usable
frequency response, this is probably a good indication that a cardinal
mistake may have been committed elsewhere in the P.A. system or
room acoustics.
An equalizer is no solution for bad equipment, but it is an extremely useful and
effective sound tool for musical fine-tuning. Fine-tuning often leads to amazing
improvements in acoustic penetration and in the overall sound quality of your
entire setup.
3.2 Equalizer in the monitor path
When using your ULTRAGRAPH PRO in the monitor path, the same applies as
when using it as described in section 3.1.
Basically, the stage volume should be as low as possible because:
1. this protects your hearing,
2. there are fewer feedback problems, and
3. it is easier to create a good FOH sound.
Often, monitor volume level is increased during a concert. Use intermissions in
the program to lower all monitor paths roughly 3 dB. The musicians will hardly
notice this reduction because their hearing can recover somewhat during an
intermission. This way you can achieve valuable headroom for possible use later
in the program.
Extremely deep frequencies are usually completely removed to avoid creating a
“queasy” feedback stage sound. To this end, use the low-cut filter and set it up in
such a way that extremely deep feedback completely disappears, creating a more
transparent monitor sound.
VP1220F
EP2000
ULTRAGRAPH PRO FBQ3102
XENYX X2222USB
Outputs
left & right
Aux sends
1 & 2
Fig. 3.2: The ULTRAGRAPH PRO FBQ3102 in a monitor system