DUAL 31- BAND GRAPHIC EQUALIZER
Correctly operating an equalizer is easier said than done. The explanation provided will direct the user on how
to make adjustments but cannot explain how to get the system to sound good, since that will come from
experience and patience.
It must first be determined how the Equalizer will be used in this system. Its primary task may be to treat
feedback, improve tonal quality, or both. Each task is explained below. If the plan is to use it for both, begin by
treating feedback first, then improve tonality second.
1. Begin with the all sliders set to the “0” position.
2. Determine the two or three frequencies that are most prone to feedback. This is best achieved through the use
of an audio frequency (or audio spectrum) analyzer but one is not required. Go directly to step #3 if you are
able to determine the frequencies of interest.
a. Treating Feedback (without the use of an analyzer)
As mentioned earlier, an analyzer is the best way for most people to determine which frequencies need
lowering. Two other methods exist but care must be taken to prevent feedback from occurring at levels
which could be damaging.
I The Boost-To-Find method is performed while the system is near feeding back. Slowly and carefully
increase one slider at a time to see how close it is to causing feedback then return it to the “0” position.
Do this one time for each slider making note of the two or three most prone to feeding back, these are
the frequencies of interest.
II The Cut-To-Find method is performed while the system is already feeding back or ringing (ringing is an
early stage of feedback). Feedback can cause damage to the system. Much care should be taken to insure
that feedback is not occurring at such levels as to cause damage. The procedure requires the lowering of
one slider at a time in an attempt to see if it’s the correct slider to affect the problem frequency. Only one
slider (out of many) will be the correct one. Assuming that the first one tried is incorrect, return it to the “0”
position and quickly try another. Repeat as necessary to locate the frequency.
3. Locate the slider that controls the feedback frequency and slowly lower the slider until the feedback stops. Be
sure not to lower the level more than the minimum amount required to stop the feedback. This will need to be
repeated as necessary to treat the worst frequencies. Usually it is not practical to treat more than two or three
frequencies as doing so will have a negative effect on tonality.
4. When finished, all but a few of the sliders will be at the “0” position. The few that were used to treat
feedback will be at approximately the -2dB or -3dB position.
5. Document your settings using the “Notes” page at the back of this manual. This will be useful in the vent that
the settings are inadvertently altered.