Phonic GEQ 1502F, User Manual

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GEQ1502F / GEQ3102F
English
3
TYPICAL GRAPHIC EQUALIZER OPERATION
GENERAL TONE CONTROL
The graphic equalizer is a useful device for general
tone shaping because it is simple and easy to adjust.
The visual reference provided by the slide fader position
gives an approximate idea of the frequency response
generated: higher frequencies appear on the right, lower
frequencies on the left. To use the equalizer, you must
know the numerical frequency range of the tone you
wish to produce. The frequency range chart, located
on page 18, is a useful tool when first using a graphic
equalizer. use the range chart as a guide, then adjust by
ear. unfortunately, even a good equalizer cannot offer
a complete solution when a room has severe inherent
acoustic problems. Nor can equalization overcome the
lack of sound clarity caused by rooms with unduly long
reverberation times.
FEEDBACK CONTROL
in live performance applications, graphic equalization is
almost always applied separately to the stage monitor or
foldback system to reduce the level of those frequencies
that would otherwise cause feedback problems. These
problems arise from monitor positioning, sound reflected
from the stage walls, and peaks in the frequency
response curves of the monitor speaker system.
a graphic equalizer can provide some control over
moderate feedback problems, but it hasn’t enough
flexibility or resolution to remedy a severe feedback
response. The best results are achieved by eliminating
feedback points. One or two feedback points can be
eliminated by adjusting the slide faders, but no more
than 6dB should be cut.
if you find feedback points covering many equalizer
bands and cutting every affected band does not help,
you must reduce the system gain. The combined use
of a graphic equalizer for tone control and a parametric
equalizer for feedback control is highly recommended.
MIXER CHANNEL EQUALIZATION
Many mixers provide only simple equalization for
individual channels. if your mixer has channel inserts,
you can patch your equalizer into a channel that is being
used for something important and use it to tailor the
sound of this channel exactly as you want.
LARGE ROOM EQUALIZATION
Large rooms tend to suffer from multiple reflections with
long time delays and long reverberation intervals factors
which lead to reduced intelligibility and a generally
muddy sound. as sound travels long distances, high
frequencies attenuate more than low frequencies. in
general, a large room benefits from some low frequency
roll-off and some high frequency boost. Therefore,
reducing the low frequency output may be advantageous
in buildings made of concrete or stone, where much of
the bass is reflected rather than absorbed. Rolling off the
high frequency end above 5khz may also contribute to
a more natural sound. The shape of the optimal house
curve varies according to the individual sound system
and acoustic environment; a degree of experience is
indispensable to achieving the best result.