Equalizer Operation

An equalizer is used to change the frequency response of an audio system. This enables the sound technician or the user to make adjustments that enhance the quality of the audio produced. However, it is well to remember that a sound system is like a chain, it is only as good as its weakest link. Poor microphones or speakers, et cetera can only be partially compensated for by a good equalizer.

A speaker that is not producing an even output, where some frequencies are louder than others, can be smoothed out by adjusting the slide controls on a graphic equalizer. This takes a sharp ear and a degree of experimental adjustment for the inexperienced user. The sound coming from the speaker can seem to be too harsh and lacking in base.

Where the speaker is mounted in a room can make a significant difference as to the sound quality. A speaker mounted high up and in the corner of a room will actually increase the bass, sometimes so much that it must be adjusted for with the graphic equalizer.

The shape of a room, the construction of the walls, ceiling and floors and even the presence of people (who actually absorb sound and prevent echoes) can be a factor. Although some echoes cannot be removed, some clarity of sound can be gained by reducing some of the base frequencies.

Feedback can be reduced with 1/3 band equalizers. This is done by turning up the volume on a microphone until a squeal is heard. Then by turning down a specific frequency associated with the squeal. Thus the feedback can be eliminated. This means you can then increase volume a little more and adjust again for feedback. There is, of course, a limit on how much volume can be gained in this manner. Some new equalizers come with an automatic feedback controller. It can sense the feedback and puts a narrow filter on the frequency in question.

Generally, in an in-place sound system, the original settings of the equalizer are determined by a sound technician using a special (and expensive) instrument called an RTA (real time spectrum analyzer). Be sure to note where all the settings are on the equalizer after the job has been done, (in case some unauthorized person makes some radical adjustments).

< Parametric Equalizers | Equalizer Terminology and Definitions >

Interesting Fact:

When an equalizer has been installed in a permanent location and the optimum adjustments have been made, it is a good idea to record the equalizer settings just in case...


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