 An audio equalizer is a usual part of home stereo systems. It is used to adapt or control the frequency response features of an audio system. An audio equalizer provides more precise control of tone or frequency than usual treble and bass controls. There are many kinds of equalizers. The two most common are parametric and graphic.
A graphic equalizer is the simplest type among equalizers. It consists of multiple sliders or controls for cutting or boosting frequencies or bands of sound. For example, a typical five-band graphic equalizer has sliders for five fixed frequencies: 30Hz (low bass), 100Hz (mid-bass), 1 kHz (midrange), 10 kHz (upper midrange) and 20 kHz (treble or high-frequency). It can cut or boost each frequency within a range of +/- 6dB or maybe +/- 12 dB, that depends on the model, but each frequency is fixed. A ten-bend equalizer controls ten fixed frequencies that allow greater tone control.
Parametric equalizer is more complex kind. It controls more parameters of the sound than a graphic equalizer. Three aspects of each frequency can be controlled by a parametric equalizer. These aspects are: level (cut or boost), the center or primary frequency and the bandwidth or range of each frequency. The same like a graphic equalizer, parametric equalizer can increase or decrease each frequency by +/- 6dB or maybe +/- 12 dB. Moreover, a parametric equalizer can control the center frequency. For example, if the graphic equalizer has a fixed control at 20Hz, a parametric equalizer can be adjusted to control a center frequency of 15Hz, 25Hz or 30Hz, etc. There are different models, but the center frequency but the center frequency can be varied to adjust a specific frequency. A parametric equalizer can also control the bandwidth or range of each control. A parametric equalizer can vary the bandwidth or range of control by making its affect wider or more narrow depending on needs or personal tastes.
In conclusion, if you need an audio equalizer, consider buying a parametric equalizer that allows much more detailed control of the sound and permits finer adjustments than a graphic equalizer.
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