The Difference Between a Graphic and a Parametric Equalizer

Learn about these audio equalizers used with stereo systems

Audio equalizers are used to alter the frequency response characteristics of an audio system. When discussing the topic of audio equalizers, one may initially think of the types found in home theaters and/or car stereos. However, many modern audio or audio-related devices have some form of a built-in audio equalizer.

It could be as basic and simple as a portable Bluetooth speaker that has knobs to adjust bass and treble levels. Or it could be a touch more robust, such as what is often featured within audio/music apps for mobile devices or software for PC/desktop sound cards.

The Importance of Audio Equalizers

The best audio equalizers are designed to provide greater and more accurate control over tone and frequency – a significant leap beyond just simple bass and treble knobs. They can raise (boost) and lower (cut) the decibel output of specific bands (frequencies of sound).

Some home stereo receivers/amplifiers offer built-in audio equalizer controls with varying levels of complexity. You might see them represented by an array of individual sliders or dials. Or they could be presented digitally through an LED/LCD screen and modified by buttons on the unit or remote.

If your receiver/amplifier doesn't allow you to tweak a system's sound output the way you like, you can get a separate audio equalizer to do just that. While there are many types of audio equalizers, the two most common to choose from are graphic and parametric. Here's what you should know about them.

Music Equalizer Bars
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Graphic Equalizers

A graphic equalizer is the simpler type of audio equalizer, most often sporting multiple sliders or controls for boosting or cutting bands. But the number of individual controls can vary by make and model. For example, a typical five-band graphic equalizer will have sliders for five fixed frequencies: 30 Hz (low bass), 100 Hz (mid-bass), 1 kHz (midrange), 10 kHz (upper midrange), and 20 kHz (treble or high-frequency). A ten-band equalizer has sliders for ten fixed frequencies – typically the ones previously mentioned along with other values in between those. More bands mean wider control over the frequency spectrum. Each of the fixed frequencies can be boosted or cut to a maximum/minimum degree. The range could be +/- 6 dB or perhaps +/- 12 dB, all depending on the make and model.

How Graphic Equalizers Are Unique

But there is one main thing to understand about using a graphic equalizer; when you adjust a slider, it also affects the neighboring frequencies. Think about what happens when you poke a finger into a plastic wrap that's covering a bowl. As the finger presses down into the plastic, it creates a slope effect. The areas closest to the finger are more affected by the sloping than areas further away. Pushing harder also intensifies the sloping versus a light poke. This same principle applies to how graphic equalizers handle frequency adjustments when boosting/cutting bands.

In a nutshell, graphic equalizers offer:

  • Simple and intuitive operation
  • Fixed frequency adjustment
  • A Broad range of effect
  • Ideal for general use
  • Typically less expensive than parametric equalizers

Parametric Equalizers

Parametric equalizers are more complex than graphic equalizers since you can make additional adjustments beyond volume. A parametric equalizer lets you control three aspects: levels (boosting or cutting decibels), the center/primary frequency, and bandwidth/range (also known as Q or quotient of change) of each frequency. As such, parametric equalizers offer more of a surgical precision when it comes to affecting the overall sound.

Like the graphic equalizer, each frequency can have an increase/decrease to decibels/volume. But while graphic equalizers have fixed frequencies, parametric equalizers can choose a center/primary frequency. For example, if a graphic equalizer has a fixed control at 20 Hz, a parametric equalizer can be adjusted to control frequencies at 10 Hz, 15 Hz, 20 Hz, 25 Hz, 30 Hz, and so forth. The selection of adjustable frequencies (e.g. by ones, fives, or tens) varies by make and model.

How Parametric Equalizers Control Bandwidth and Range

A parametric equalizer can also control bandwidth/range – the sloping that affects neighboring frequencies – of each individual frequency. For example, if the center frequency is 30 Hz, a wide bandwidth would also affect frequencies as low as 15 Hz and as high as 45 Hz. A narrow bandwidth might only affect frequencies as low as 25 Hz and as high as 35 Hz. While there is still a sloping effect, parametric equalizers are better able to zero in on and fine-tune the shape of specific frequencies without disturbing others too much. This detailed control of tone and sound permits finer adjustments in order to suit particular/personal tastes and/or goals (such as for mixing or recording).

In a nutshell, parametric equalizers offer:

  • Complex and deliberate operation
  • Select frequency adjustment
  • Precise range of effect
  • Ideal for studio recording, mixing, and/or production
  • Typically more expensive than graphic equalizers
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