The EQ could be as basic as a portable Bluetooth speaker with knobs to adjust bass and treble levels. Or it could be more complicated, such as the graphic equalizers found in some music apps.
The Importance of Audio Equalizers
The best audio equalizers provide greater and more accurate control over tone and frequency—a leap beyond just bass and treble. They can boost or cut the decibel output of specific frequency bands. Some home stereo receivers or amplifiers offer built-in audio equalizer controls with varying levels of control, including individual sliders or dials. They might also have digital displays controlled via remote. If your receiver or amplifier doesn’t allow you to tweak a system’s sound output the way you like it, use a standalone audio equalizer. While there are many types of audio equalizers, the two most common are graphic and parametric. Here’s what you should know about them.
What Are Graphic Equalizers?
A graphic equalizer is the simpler type of audio equalizer, most often sporting multiple sliders or controls for boosting or cutting bands. The number of individual controls can vary by make and model. For example, a typical five-band graphic equalizer has 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 mentioned above as well five more frequency bands. More bands mean wider control over the frequency spectrum. Each of the fixed frequencies can be boosted or cut to a maximum or minimum degree. Depending on the make and model, the range could be +/- 6 dB or perhaps +/- 12 dB.
How Graphic Equalizers Are Unique
There is one important thing to understand about graphic equalizers. 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 or cutting bands. In a nutshell, graphic equalizers offer:
Simple and intuitive operationFixed frequency adjustmentA broad range of frequency controlA less expensive package than parametric EQs
What Are 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: level (boosting or cutting decibels), the exact frequency, and the bandwidth or range (also known as Q or quotient of change) of each frequency. As such, parametric equalizers offer surgical precision when it comes to affecting the overall sound. Like the graphic equalizer, each frequency can be cut or boosted. But while graphic equalizers have fixed frequencies, parametric equalizers can choose a center or 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 (for example, by ones, fives, or tens) varies by make and model.
How Parametric Equalizers Control Bandwidth and Range
A parametric equalizer can also control the bandwidth—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. This detailed control of tone and sound permits finer adjustments to suit particular tastes or objectives (such as for mixing or recording audio). In a nutshell, parametric equalizers offer:
Complex and deliberate operationSelect frequency adjustmentPrecise range of effectPerformance for studio recording, mixing, and productionA more expensive package than graphic equalizers
