A master guide to voice equalization—how to apply EQ to voice recordings

It’s easy to ruin a good voice recording with heavy-handed equalization.

I’ve heard voiceovers that sound like the speaker had a stuffy nose even when they didn’t. I’ve heard voiceovers that sound like the speaker was talking in a high-pitched voice—when they weren’t. I’ve even heard voiceovers where the speaker sounds so odd that the recording becomes simply unintelligible.

The unfortunate thing here is all of these voice recordings started with a great-sounding clean voice. But they were butchered with aggressive, incorrectly applied EQ.

The good news is you don’t need to be an experienced audio engineer to apply EQ that improves a voice recording, rather than ruining it.

In this tutorial, I’ll show you how to approach equalization before discussing EQ specifically for voice.

It’s All Over Before You Know It

Before I start talking about EQ, I want to ensure you have the right frame of mind when it comes to recording voice.

The character and tone of any voice recording are decided long before you load up the DAW or audio editor and apply some EQ.

If you want your voiceover to sound warm, you need to create this warmth in the recording phase. Too many people try to create warmth with EQ.

And unfortunately, that’s not how it works. You can’t create new frequencies and completely change the character of a recording. You can only exaggerate or lessen what is already there. Sure, these processes can make a voice sound warmer, but the warmth needs to be there in the first place.

woman recording in a studio — There has to be warmth in your recording if you wish to bring it out with EQ - Image from Envato Elements.

Before you load up an EQ to change the character of the voice -- stop. If you don’t like the tone of the voice recording, you might have to start again.

Next time you record, think about what character and tone you want to capture. Avoid thinking that you’ll make it sound better with EQ and compression later on. That’s just not how it works. Take the time to get the recording to sound good from the outset. you will have a far better final product this way rather than trying to make a million adjustments after the fact.

Now with these caveats out of the way, let’s move on to how to use an equalizer properly.

How To Use An Equalizer

Equalizers are not to fix the character of a voiceover but they can bring out more of what makes the recording good. Or, they can remove what makes the recording bad. It’s that simple.

An equalizer can’t add what’s not there in the first place.

They can also be used to change the character of a voice, but only slightly. And they can be used to improve a voice recording, but only if it’s a good recording already.

Got it? Good. Now on to the practical application.

When you’re first starting out, you should only approach EQ in two ways. Later on, you can experiment -- once your ears are better trained. But to begin, stick to these two approaches and you can’t go far wrong.

The first approach is to use narrow cuts to remove room resonances and unpleasant elements of the sound.
The second approach is to use wide boosts to exaggerate the good stuff.

But here there are also two golden rules to consider at all times:

Try to use cuts more than boosts. This is called subtractive EQ. Without going into too much detail, it’s always better to cut. So if you want something to sound brighter, cut the lows instead of boosting the highs.
Subtlety is key—especially when it comes to voice. Avoid cutting or boosting more than 3-5 dB. Any more, and the voice will start to sound unnatural and odd.

single band bell curves — Single band bell curves, as shown in Logic Pro.

It’s also worth bearing in mind that these approaches only apply to single bands—bell curves—on the EQ.

Shelves are something else to pay mind to. They boost or cut everything below or above a certain frequency. A low shelf will boost or cut everything below it, and a high shelf will boost or cut everything above it.

The golden rules still apply to these: cut before boosting, and keep it subtle.

shelf EQ — Shelf EQ as shown in Logic Pro.

Filters completely cut everything below or above a certain frequency. A high pass filter will cut everything below it. It lets the highs pass. And a low pass filter will cut everything above. It lets the lows pass.

The golden rules don’t apply to these: you can only cut with filters—there’s no option to boost—and you can’t limit them to 3 dB’s—because they cut everything.

There we have it - three types of EQ, two approaches, and two golden rules. Remember these and you can EQ anything. Just use your ears.

Applying EQ to a Voice Recording

Now, let’s consider EQ in relation to voice recordings.

First, apply the general principles that I have just discussed. Move the EQ bands around until you find any room resonances, and cut them by 3 dB. Move the bands around until you find pleasant elements of the sound, and boost them by 3 dB.

No two voices are the same, so warmth in one voice will be in a slightly different place to another. You’ll need to play around a bit to find what works. And there will be distinct differences between masculine-sounding and feminine-sounding voices. Masculine voices are centered around 80-180 Hz, whereas feminine voices are centered around 160-260 Hz. That’s a big difference.

Having said that, there are a few areas that are common across all voices. Only use the following tips as guidelines and starting points. It’s important to experiment. Use your ears and find what works for the particular voice.

Before I start, here’s the voice recording with no processing:

1. Use a High Pass Filter to Cut Everything Below 80 Hz

This is a common practice and something that you can do to improve any voiceover. Anything below this frequency will be low-end rumble and noise. Remove it, and it will instantly clean up your voiceover.

Try going even higher, especially on a female-sounding voice. If your voice recording is sounding a bit too bass-heavy, cutting everything below 100 Hz will really help with intelligibility.

Here is the voice recording with a high pass filter applied at 80 Hz:

2. Cut 100-300 Hz to Add Clarity

Similar to the last tip, cutting the bass will improve clarity. On the other hand, if the voice sounds a bit thin, try boosting somewhere in this frequency range.

Here is the voice recording with a cut from 100-300 Hz:

Here is the voice recording with a boost from 100-300 Hz:

3. Cut 300-400 Hz If the Voice Sounds ‘Muddy’

This is a problematic frequency range for most recordings—particularly in music. If the voice sounds too muddy, try cutting somewhere around this area.

Here is the voice recording with a cut from 300-400 Hz:

4. A Wide Boost Between 2-6 kHz Can Improve Clarity

If cutting some of the bass around 100-300 Hz doesn’t add enough clarity, try a gentle boost across this frequency range.

Here is the voice recording with a boost from 2-6 kHz:

Be careful of exaggerating the sibilance and S sounds of the voice though, which leads me to the next step:

5. Cut Around 3-5 kHz If the Voice Sounds Too Sibilant

Be wary of this frequency range when boosting. Boosting too much at these frequencies can make the voice sound highly sibilant and add too much sizzle.

Here is the voice recording with a cut from 3-5 kHz:

Addressing Common EQ Issues in Different Environments

When applying EQ to voice recordings, the recording environment plays a critical role in shaping the sound. Different environments present unique challenges that may require specific EQ adjustments to achieve the best results.

female podcaster recording at home — The EQ choices you make will be different for voice recordings made at home versus those made outdoors. Image from Envato Elements.

Below are some common recording environments and tips on how to adjust EQ settings to address their particular issues.

1. Home Studios

Home studios often have imperfect acoustics, which can lead to issues like room resonances, echo, or background noise. Here’s how to adjust EQ in such environments:

Tackle room resonance: Home studios may have resonances caused by untreated walls, floors, or ceilings. To reduce these, use a narrow cut (around 3-5 dB) to identify and remove resonant frequencies, usually found between 100-300 Hz.
High-pass filter for low-end rumble: If you’re picking up hums or vibrations from things like HVAC systems or traffic, apply a high-pass filter to remove everything below 80-100 Hz.
Clarity boost: Home recordings can sometimes sound muffled or muddy, especially in untreated rooms. Consider a wide boost around 2-6 kHz to increase clarity and make the voice stand out.

2. Professional Studios

Professional studios are generally designed to control acoustics, so the raw recordings should be clean and clear. However, EQ can still enhance recordings:

Subtle adjustments: Since professional recordings tend to be cleaner, EQ adjustments should be minimal and subtle. Focus on emphasizing pleasant frequencies rather than cutting problematic ones.
Warmth enhancement: In a controlled studio environment, you can emphasize the warmth of a voice by applying a gentle boost around 100-300 Hz, but be cautious not to overdo it, as it can make the voice sound overly bass-heavy.

3. Outdoor Environments

Recording outdoors can introduce a variety of issues, including wind noise, environmental sounds, and an unbalanced frequency response. Here’s how to handle outdoor recordings:

Aggressive high-pass filter: Outdoor environments often introduce low-frequency noises such as wind or distant traffic. Use a high-pass filter set at a higher frequency—around 120-150 Hz—to eliminate these unwanted sounds.
Cut mid-range frequencies: If your recording has an unnatural boxy sound caused by reflections from nearby objects like buildings or vehicles, try a narrow cut around 400-600 Hz to reduce this.
Restore lost highs: Outdoor recordings may lack the natural brightness of a studio environment. Apply a wide boost around 6-10 kHz to regain some high-end sparkle, but be careful not to introduce excessive sibilance.

4. Portable Recording Setups (On the Go)

Recording on the go with portable equipment like handheld recorders or smartphones) often results in compromised audio quality due to uncontrolled environments. Here’s how to make the best of it:

Remove background noise: Since portable setups may pick up a lot of ambient noise, a high-pass filter at 100 Hz or higher will help clean up the recording.
Address plosives and proximity effects: If the microphone was too close to the speaker, the recording might have a "boomy" quality. Apply a narrow cut around 80-150 Hz to reduce excessive bass caused by proximity effects.
Boost clarity: Portable recorders may not capture the full richness of the voice. A wide boost around 3-5 kHz can improve intelligibility and add clarity to the recording.

Final Thoughts

Remember that these tips are purely intended to be used as starting points. Experiment, and trust your ears.

But remember that subtlety is key. Spend time getting the sound that you want when you record. Only then should you use EQ to improve it. EQ is a supplement to make a good recording great. It can’t make a bad recording good.

Best of luck as you explore the true power of EQ!