How to EQ Audio for Better Headphone and Speaker Sound

Whether you're listening in your living room, in your car or on a plane, you can make audio sound the way you want using a simple equalizer (EQ). It can even help compensate (to an extent) for suboptimal headphones or speakers. EQ can't make a bad audio product sound great, but it can often improve (or at least change to your liking) the sound of most gear.

Equalization means manually rebalancing various frequencies that make up the audio we hear, either using software and apps or hardware knobs and sliders. The result is that the audio sounds "better"-- a subjective term, to be sure. Equalizers break the audible frequency range into segments, called bands, and you can make those bands louder or softer. Some devices have this built in; others have it in their mobile apps. You can also find third-party apps and software that can help, too. 

Nearly all home A/V equipment and car audio systems have some form of EQ, either via a screen or physical controls. Many Android phones and tablets have a built-in EQ (accessible in the sound settings) that affects all audio coming from the device. Apple's iOS devices are limited to 22 presets in the Music app settings.

Most music-streaming apps also include a mix of presets and graphic EQ sliders (more on these below). Wireless headphone companion apps often offer similarly robust EQ features, but video apps like Netflix and Disney Plus don't have EQ at all, making third-party EQ apps from Google Play or Apple's App Store necessary if you want more rumble in your explosions or better dialogue clarity. 

EQ basics 

The range of frequencies most humans can hear fall between a super deep 20 hertz and an ultra high 20,000 kilohertz. That's what a baby with perfect hearing can likely hear. Everyone loses hearing over time, especially in the high frequencies, so middle-aged and older adults won't be able to hear frequencies over 12,000Hz nearly as well as younger people. Broadly, though, these are the ranges adjustable with most EQs.

With an EQ, you can boost certain frequencies to get more of what you want or reduce frequencies you don't. You are limited to how much you can do with both, but adding additional volume is more difficult as all gear has limits to how much louder it can be without causing issues like distortion. 

One of the most common types of EQ is called a graphic equalizer, which gives you control over specific frequency bands and has a visual element to help you see how the adjustments are affecting the frequency spectrum. These can have any number of bands and frequencies to adjust, but usually there are fewer than 10. More advanced models can have many more than that.

Another common type is called a parametric EQ. These don't have the visual element of graphic EQs but tend to have finer adjustments and more flexible control. They can typically do more than graphic EQs but require more knowledge to get the most from them.

Many apps just have EQs with simple sliders that boast a broad range of frequencies. They're not as easy to use or adjustable as graphic and parametric EQs, but they can still help.

EQ by the numbers

To help explain what EQs do, I'll break the audible range into six bands. Your EQ might have more options or fewer, but this should give you an idea of what range does what. Also, the names and specific frequency ranges vary a bit, depending on the product. Ideally, the EQ will list the specific frequencies it can adjust, but often they're just vaguely labeled with terms like these.

Sub-bass: 20-60Hz

These are the lowest, deepest audible frequencies, more felt than heard, and they will literally shake walls if your system is big enough. To hear these sounds well usually requires a subwoofer, which is where the depth and weight of bass sounds come from, as well as the rumble of movie explosions. Cranking this up in your car or stereo will make it feel like you're in the club or movie theater. Some of the best headphones can reproduce these super low sounds, but not all.

Bass: 60-250Hz

This range -- especially the top of it, called upper bass -- is commonly boosted by default in many popular headphones. Increase this range to bring out acoustic and electric bass (the instrument that is), kick drums, timpani and the impact of explosions. If the sound is muddy or the bass is overpowering vocals or dialogue, experiment with cuts in this range. 

Lower mids: 250-500Hz

This is where the warmth of vocals, guitars and keyboards lives. This is also where much of the "punch" of bass lives. Boost for extra richness and bass presence. Cut to reduce overall muddiness and combine with an upper-mid boost to make vocals and dialogue clearer.

Midrange: 500-2,000Hz (2kHz)

This is the "meat" of most instrument and voice tones. Give these a very light boost to bring out piano and guitars. Cut slightly if those instruments are overpowering vocals.

Upper mids: 2-4kHz

These frequencies are most responsible for the clarity of dialogue, vocals and instruments. Boost gently to bring out speech or give the front ends of notes a little extra definition. You'll want to cut these a tiny bit if vocals or instruments feel harsh or grating. Boosting the transitional range between the upper mids and highs can add presence and sparkle to cymbals and acoustic instruments.

Treble/Highs: 4kHz and up

This highest range is where sounds get their "sparkle" or a "crystalline" sound as well as sibilant sounds, "air," and breathiness. Think cymbals, small bells or the air in a trumpet or sax sound. You can add a boost here to bring out subtle nuances, especially effective on higher-end sound gear that can reproduce the highest audible frequencies well. If sibilants sound harsh or the overall sound has a slight hiss to it, make a slight cut to darken up the sound a bit. Too much treble can be fatiguing to listen to.

EQ gently and listen, listen, listen!

If you're not sure how a specific band changes the sound, increase its volume until you hear the difference. That's far easier than trying to hear a reduction in volume in a range. Once you've determined what the control does, make small, 2 to 3 decibel (dB) adjustments until you've gotten it sounding how you want. You may need to adjust, listen and adjust again, potentially a few times, until you find the sound that moves you most. 

Also, and this is important, use a variety of different songs and styles, unless you want to make presets for every genre you enjoy. Which is to say, don't be afraid of using presets; these are just shorthand steps that combine one or more of the adjustments above. Let your ears be your guide.