General Tone Control; Feedback Control; Console Channel Equalization; Large Room Equalization - Ashly GQX-1502 Operating Manual

Page - 8
Safety Instructions – 3
Introduction - 4
GQX Equalizers – 5
Connectors & Cables – 5
Physical Description - 6
Installation – 7
Typical Applications - 8

General Tone Control

Feedback Control

Console Equalization
Room Equalization
Troubleshooting - 9
Dimensions - 9
Specifications - 10
Warranty - 11
The following information will help you make the most of your new equalizer:
General Tone Control
The graphic equalizer is a very useful device for general tone shaping because it is intuitive
and easy to adjust. The visual reference provided by the slider position gives an
approximate idea of the frequency response generated, with the lower frequencies on the
left and higher frequencies on the right. To use the power of an equalizer effectively, you
need to translate your idea of the tone you want to produce into a range of numerical
frequencies. This is simple after a little practice. Here are a few references which are
useful for starting points:
Very low bass (the "wind" in a kick drum, almost felt as much as heard -40Hz-
80Hz.
The low register of a male voice - 200Hz
The low register of a female voice - 350Hz
Lower midrange ("warmth" frequencies) - 400Hz-1KHz
Upper midrange ("harshness", snare drum "bite", "hot" sound) -2.5KHz-4KHz.
Sibilance ("sss" sounds, cymbal "sizzle") - 8KHz-15KHz.
Try using these starting points as a guide when you want more or less of these types of
sounds. Adjust by ear from there. It is always a good idea to remember that a little
equalization usually works out much better than a lot, and that there are many audio
problems which can not be solved with equalization alone.
Feedback Control
A graphic equalizer can be used to provide some control over moderate feedback
problems, but does not have enough flexibility or resolution to handle severe situations.
You will achieve the best results when you can eliminate one or two feedback points by
setting one or two sliders for no more than a 6dB cut. Often you can find a feedback point
by boosting sliders in succession to determine which frequency ranges contain the
feedback modes, and then cutting those ranges. Be very careful in this process to avoid
explosive feedback and possible system and hearing damage. If you find feedback points
with many equalizer bands, cutting every band may not help (all you will do is reduce
system gain). The combination of a graphic equalizer for tone control and a parametric
equalizer for feedback control is highly recommended.

Console Channel Equalization

Many mixing consoles provide only simple equalization for individual channels. If your
console has channel inserts, you can patch your graphic equalizer into a channel requiring
more precise equalization.

Large Room Equalization

Large rooms tend to suffer from multiple reflections with long time delays, long
reverberation times, and "ringmodes", all of which lead to reduced intelligibility and a
generally "muddy" sound. As sound travels long distances through the air, high
frequencies are attenuated more than low frequencies. In general, large rooms benefit from
some low frequency roll-off, high frequency boost, and attenuation of ring mode
frequencies. As in the case of feedback control, a graphic equalizer can help reduce an
isolated ring-mode or two, but a tunable narrow-band equalizer such as a parametric is
more effective here.
Copyright© 2007 – Ashly Audio Inc.
Operator Manual – GQX Series Equalizers