How to Adjust Frequencies on a Stereo Audio Equalizer

Spend less than 30 minutes to sculpt and fine-tune audio with equalizer controls

A graphic stereo equalizer represented in green
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So you've got your stereo system connected and the music is sounding pretty good. But can it get even better? Of course! One of the easiest and most convenient tools for adjusting audio is probably right at your fingertips. Old-school equipment usually features physical sliders (analog) on the front, while modern models incorporate such controls in a graphical digital form (or sometimes as part of an app or software, depending on one's set-up).

A stereo audio equalizer, commonly known as 'EQ controls,' allows the adjustment of specific frequency bands. Quite often, these controls offer a selection of one-click presets such as (but not limited to): flat, pop, rock, concert, vocals, electronic, folk, jazz, acoustic, and more.

Much like with the taste of food, listening to music is a subjective experience. Whether a casual listener or dedicated audiophile, people tend to have certain preferences. Some of us opt to augment our meals with a sprinkle of spices such as salt, pepper, cinnamon, or salsa. The same concept applies to audio, and the equalizer controls provide that element of customization. Remember, only you get to know and decide what sounds good to your ears, so trust in what you hear and enjoy!

Sometimes the use of a stereo audio equalizer can be less about enhancement and more about bridging a deficit. Different brands and models of speakers exhibit unique sonic signatures, so the equalizer can help sculpt and fine-tune the output.

Maybe a pair of stereo speakers puts too much emphasis on the lows and highs. Or maybe there's a frequency dip that needs to be smoothed out. Either way, different speakers may require different settings, and judicious use of the equalizer controls can help improve overall sound without too much effort.

Most people don't own and use a real-time analyzer, which is perfectly ok. The best way to learn how to adjust a stereo audio equalizer is by ear, using personal listening preferences as a guide. It helps if you have and use some favorite audio test tracks. Everyone has different opinions about the best sound, so use the following steps to adjust an equalizer to your tastes. Just keep in mind that small adjustments can go a long way for perfection.

Difficulty: Easy

Time Required: 30 minutes

Here's How

  1. Ensure correct speaker placement. Before you even touch the equalizer, make sure that all speakers are placed correctly. If the speakers aren't already positioned to sound their best, adjusting the equalizer controls won't create the sought-after impact. If you don't know how to or are unsure, follow proper placement guidelines to help correctly set speakers. By doing so, you will be starting from the best sound possible in your listening room.

  2. Set equalizer controls to neutral. Start with the equalizer controls (whether hardware and/or software) set at the neutral or ‘0’ position. You don't know who may have touched them last, so it's always prudent to check the levels first. Each slider adjusts a specific frequency band, labeled in hertz (Hz), with the vertical motion increasing/decreasing the decibel (dB) output. Low-end frequencies (bass) are on the left, highs (treble) on the right, and midrange in between. 

  1. Adjust equalizer controls. Based on your opinion or listening preferences, make small adjustments (increase or decrease) to one frequency control at a time. Be sure to play music that you're intimately familiar with so you can be certain about the resulting sound. Even a small adjustment can make a big impact, as all frequencies interact with each other and affect the overall performance.

    Keep in mind that it is considered best practice to cut or reduce frequencies instead of increasing them. This may seem counter-intuitive at first since pushing the dial up results in providing more. But boosted signals can quickly erode clarity and develop unwanted distortion, which defeats the purpose of fine-tuning for best sound. So if you want to hear brighter treble in general, you would reduce the levels of midrange and low-end frequencies. Want more bass? Tone down the treble and midrange. It's all about balance and proportion.

  1. Evaluate the sound quality. After making the adjustment, allow a moment of listening to appreciate the resulting effect – changes typically don't happen immediately. You may also want to turn the volume up a bit, especially if a few frequencies have been adjusted down.

  2. Make further adjustments. Re-adjust the controls to make minor changes, or pick another frequency band and repeat step three until you have achieved the desired sound quality. It can be beneficial to play different music tracks that showcase a variety of vocals and/or instruments in order zero in on a specific sound. Don't be afraid to play and experiment with all of the equalizer settings.