How do you choose between graphic and parametric EQ for live sound?

1 Graphic EQ

A graphic EQ is a device that divides the audio spectrum into fixed bands, usually ranging from 10 to 31, and allows you to boost or cut each band by a certain amount, usually in decibels (dB). Graphic EQs are often used to adjust the overall sound of a room, a speaker system, or a monitor mix, by compensating for the acoustics, the feedback, and the tonal preferences. Graphic EQs are easy to use, as you can visually see the shape of the frequency curve, and make quick adjustments by sliding the faders up or down. However, graphic EQs have some limitations, such as the fixed width and spacing of the bands, which may not match the exact frequencies you want to affect, and the potential for phase issues, which may degrade the sound quality.

2 Parametric EQ

A parametric EQ is a device that allows you to adjust three parameters for each band: the frequency, the gain, and the bandwidth (or Q). The frequency determines the center point of the band, the gain determines how much you boost or cut the band, and the bandwidth determines how wide or narrow the band is. Parametric EQs are often used to fine-tune the sound of individual instruments, vocals, or channels, by removing unwanted resonances, enhancing specific harmonics, or shaping the tone. Parametric EQs are more flexible and precise than graphic EQs, as you can dial in the exact frequency, gain, and bandwidth you need, and avoid affecting adjacent frequencies. However, parametric EQs are more complex and time-consuming to use, as you have to adjust three knobs or sliders for each band, and rely on your ears rather than your eyes.

3 How to choose

Choosing between graphic and parametric EQ for live sound can be tricky, as both types of EQ have their own advantages and disadvantages that may be better suited for different applications and situations. Generally speaking, graphic EQs are better for broad and global adjustments, such as matching the room acoustics, controlling feedback, or setting a general tone for the mix or the monitors. Parametric EQs are better for fine and specific adjustments, such as correcting or enhancing the sound of individual instruments, vocals, or channels. If possible and necessary, it is best to use both types of EQ in combination; a graphic EQ on the main output or the monitor sends and a parametric EQ on each channel or subgroup will balance the overall sound with the graphic EQ while allowing you to fine-tune the details with the parametric EQ.

4 How to use

No matter which type of EQ you choose, there are a few tips to keep in mind for effective use. Use your ears more than your eyes - trust what you hear when adjusting the EQ, rather than focusing on the curve or fader positions. Before beginning, listen to a reference track or do a sound check with the performers to identify any issues that need to be fixed. Subtractive EQ is preferable over additive EQ as it reduces noise and feedback, and preserves the natural sound of the source. When cutting frequencies, use a narrow bandwidth to isolate and remove the problem frequency without affecting surrounding frequencies. For boosting, use a wide bandwidth to add warmth and presence without creating peaks or notches in the frequency curve.

5 How to practice

Learning how to choose and use graphic and parametric EQ for live sound can be best done through practice. Experimenting with different types of EQ on different sources and scenarios can help you understand how each type affects the sound quality, feedback, and tonal balance. Utilizing a spectrum analyzer or frequency analyzer to identify dominant, missing, or problematic frequencies can guide your EQ decisions and check your results. Additionally, seeking feedback from other sound engineers, performers, or listeners can provide valuable perspectives and experiences.

6 Here’s what else to consider

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