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Podcast Editing
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April 18, 2024

What is equalization? A podcaster’s guide to EQ (with visual examples)

Resound.fm Team

Have you ever been in a car that had the three simple knobs: Bass, Mid, and Trebble? If so, then you’ve equalized audio before! 

At its core, equalization is simply a process of adjusting the volume of specific frequencies in audio. But it can be a bit confusing, so in this blog, we will cover everything you need to know about EQ as a podcaster. 

What we’ll cover: 

What is equalization?

Equalization is the process of changing the volume of specific frequencies in your audio. It’s done with a tool called an equalizer. 

Equalization is a powerful tool that can shape the tone of how your audio sounds. You can boost the low end and cut out the high frequencies for a sound (the NPR style) or make your audio sound natural and authentic, reducing the low end. 

To understand equalization, we need to understand audio frequencies. 

The human ear can pick up sounds ranging from 20 Hz to 20,000 Hz (or 20 kHz). Equalization is the process of adjusting volume across various frequencies from 20 HZ (super low) to 20,000 hz or 20 kHZ (super high). 

Image Source: Landr

Why does EQ matter?

In podcasting, sound quality isn't just a feature—it's a differentiator. 

Here are three reasons why EQ matters in podcasting. 

1. It helps balance out sounds

Every podcast episode carries a range of sounds: The host's voice, the guest's voice, intro music, and sometimes even sound effects. Sometimes, these elements might not play well together. EQ helps to balance such sounds by boosting the bass or treble levels or cutting out certain low- or high-frequency sounds, making sure everything sounds just right.

2. It helps fix frequency masking

Ever noticed how sometimes sounds overlap, creating a kind of sonic blur? That's frequency masking. It makes it hard to distinguish between different sounds. EQ can clarify this overlap, ensuring each element in your podcast remains distinct.  

3. It reduces unwanted and distracting sounds 

Unnatural, harsh, or annoying frequencies can be a big distraction to listeners. EQ lets you target these unwanted frequencies, maintaining a clean sound throughout. Perhaps your guest has a lot of harsh sibilant sounds (“shhh”) at the start of words, so you decide to reduce the high-end frequencies to make this less painful to your listeners. 

As you can see, EQ can provide a lot of benefits. So how do you do it? Let’s dive into that next. 

How do you equalize your voice as a podcaster?

Equalization is vital for any audio recording, and as a podcaster, your voice is your primary instrument. Familiarity with EQ and its tools can significantly enhance the quality of your podcast.

Here are some tools and techniques to help you effectively equalize your voice:

1. Automatically EQ your voice with Resound Enhance 

Resound's intuitive platform offers effortless equalization, powered by AI. In a few simple clicks, you can equalize your voice, and run it through a series of post-processing to make it sound clear, crisp, and professional. 

Here’s how it works: 

Resound is an easy-to-use tool for podcasters. You can enhance your podcast audio without any technical experience. AI simplifies audio adjustments, making equalization straightforward. For more guidance, and to get the most out of your podcast editing, read The Beginner’s Guide to Podcast Editing. It's a good starting point for those new to podcast audio improvement.

2. Equalize your audio with third-party plugins in a DAW

This is the most common way to equalize your audio manually. On the one hand, it gives you much deeper control than most AI tools. On the other hand, it is complex, has a steep learning curve, and often requires downloading software. 

Stock equalizers (GarageBand, Audacity, Pro Tools, etc) 

The simplest solution is to use the built-in (aka “stock plugin) equalizer in your Digital Audio Workstation. Every DAW includes an equalizer, including GarageBand, Audacity, ProTools, Audition, and Hindenburg. Believe it or not, these tools are incredibly high quality and can get you a long way. 

If you want to go a step further, you can buy a third-party equalizer plugin. We’ll share three. 

FabFilter Pro-Q

FabFilter Pro-Q is an equalizer plugin that adjusts and balances frequencies in your podcast. It reacts to the content, making your audio clearer and more listener-friendly. Using FabFilter Pro-Q can help podcasters achieve a smoother and more professional sound.  Here is how FabFilter Pro-Q helps to equalize your audio:

Image Source: Dynamic EQ using FabFilter Pro-Q 

iZotope Neutron EQ 

iZotope Neutron EQ  is a channel-strip plugin primarily designed for instrument or submix duties. Its intuitive user interface and features can be employed to refine and enhance the vocal clarity and quality of podcast episodes, ensuring a smooth listening experience for the audience.

The visual representation of Neutron offers a drag-and-drop EQ system. Here's how you use it:

Image Source: iZotope Neutron EQ module

Izotope Ozone Pro Equalizer

Izotope Ozone Pro is a tool that helps podcasters ensure their episodes sound polished and professional. If you want to focus on specific frequencies, Ozone lets you customize the display. It offers two EQ modes: analog, for a traditional feel, and digital, which can help prevent sound distortions.

Image Source: iZotope Ozone Pro Module

3. Equalize your audio with outboard gear 

The Rodecaster Pro II is a state-of-the-art multi-channel mixer tailored for podcasters. It offers an all-in-one solution with features like ultra-low-noise Revolution Preamps for crystal clear voice recordings, multiple Neutrik™ combo inputs to accommodate various microphones, and intuitive touchscreen controls. Integrated Bluetooth allows seamless addition of phone interviews, while its SMART Pads enhance episodes with on-the-fly voice effects and jingles. 

Though the Rodecaster Pro II offers unparalleled audio quality with its advanced features, its price and learning curve might be challenging for beginners on a budget. It starts at $699.          

Image Source: Rode

How an equalizer works

Before we delve too deeply into an equalizer's settings, let's break down the fundamentals. How does an equalizer even work? 

Frequency

How low or high is the pitch?  

Screenshots taken in GarageBand

Frequency refers to how often a wave completes a cycle in one second. It's measured in Hertz (Hz). In EQ settings, the frequency is central to the adjustments you make. It specifies the sound range where you'll boost or reduce levels.

Gain

How loud is a specific range of frequencies? 

Screenshots taken in GarageBand

Gain refers to the adjustment of a signal’s amplitude. It determines how much you amplify or reduce a sound using your EQ. This adjustment is quantified in decibels (dB) — positive values indicate amplification, while negative values denote reduction.

When you tweak EQ settings, you're also affecting the overall gain of your signal. Consequently, aggressive EQ adjustments can significantly change your sound levels.

Q (Bandwidth) 

How wide is the area of frequencies being adjusted? 

Screenshots taken in GarageBand

Bandwidth is the frequency range that an equalizer can alter. Q stands for quality factor. Consider it to be the bandwidth of an EQ band.

Q values less than one result in larger EQ curves, whereas values greater than one result in tighter, more selective boosts or cuts.

Adding it all up: A real world example

Below is a sample of what an equalizer might look like on a podcaster's voice who has a slightly higher pitched voice.

Screenshots taken in GarageBand

Additive and subtractive equalization

Every equalizer gives you two main options: Increase or decrease a frequency’s volume. 

Additive equalization is when you increase the volume of a frequency or set of frequencies. 

Subtractive equalization is when you decrease the volume of a frequency or set of frequencies. 

Additive and subtractive equalization are both at your disposal in most equalizers you use, so you’ll learn to use both over time. 

The 4 types of equalization filters 

Modern equalizers come with several different types of filters that you can adjust. Each filter is represented by a shape that visualizes how the volume of a set of frequencies is being changed. 

Common filters include the high-pass filter, bell, and shelf. Each filter has a width or slope, determining how steep or gradual the adjustment is. 

Here are the primary filters:

1. Parametric/Bell/Peak filters

These are highly versatile filters. They can make minute adjustments to a tiny range of frequencies or broader changes that alter the tonal character.

This filter is helpful when you want to emphasize or diminish specific tonal characteristics within a speaker's voice. It often operates in the mid-frequency range and is recognizable by its bell-like shape.

2. High pass filters (HPF) and low pass filters (LPF) 

HPFs eliminate frequencies below a chosen point, allowing higher frequencies to pass. LPFs, on the other hand, block frequencies above a chosen point, emphasizing the lows.

An HPF can remove unwanted low-frequency noise, such as traffic sounds or air conditioning hums. LPFs can remove high-pitched hissing or interference.

3. Band-pass filters

This filter is effectively a combination of a high-pass filter and a low-pass filter. It only allows a specific range of frequencies to pass through, eliminating both the highs and lows outside this range. These filters are ideal for creating special audio effects. For instance, to mimic the sound of a distant radio or a telephone conversation.

4. Notch or Band-Rejection Filters

These remove a narrow band of frequencies but leave most of the audio signal untouched and are highly effective for eliminating specific unwanted noises, such as a persistent ground buzz.

Parametric EQ vs graphic EQ

Equalizers adjust audio frequency responses to balance and improve sound quality. The two main types, parametric and graphic EQs, offer different approaches:

1. Parametric Equalizer (most common) 

Parametric equalizers provide advanced control compared to graphic equalizers. While graphic equalizers operate on predetermined frequencies, parametric ones allow users to choose a central frequency to target and modify its intensity. Moreover, they let you define the bandwidth or range for each frequency, offering precision in sound modification.

For those looking for a comprehensive tool, the FabFilter Pro-Q 3 is a notable equalizer plugin that offers parametric, linear phase, and dynamic EQ capabilities.

Image Source: Fabfilter

For podcast beginners, utilizing a parametric equalizer can significantly improve audio quality. Here’s how to go about it:

2. Graphic Equalizer

A graphic equalizer resembles a control panel with multiple sliders, each corresponding to a distinct frequency. For instance, a five-band graphic equalizer might cover frequencies from 30 Hz (low bass) to 20 kHz (high-frequency or treble). The appeal of graphic EQs lies in their visual representation, making adjustments intuitive.

By adjusting these sliders, you can turn up or down specific frequencies, providing a visual guide for sound tweaking. A prominent example of this is the Waves GEQ, available in classic and modern versions. This graphic equalizer offers 30 precise EQ bands and incorporates variable-frequency high and low-pass filters, along with a versatile parametric bell EQ.

Image Source: Waves

Final Thoughts

Equalization is more than just a technical aspect of podcasting; it ensures your content is clear, balanced, and easy to listen to.  

For those who might find the technicalities of EQ daunting, there are straightforward solutions like Resound. With its user-friendly interface, Resound simplifies the process, ensuring your podcast sounds its best with a few easy clicks (and no downloads).

Automate your podcast editing for FREE today.

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Resound.fm Team

Resound's team is building the future of podcast editing: An AI podcast editing app for creators. Here at Resound we're writing about the creative process to help content creators thrive. Picture is Ernst Chladni, the inspiration for our brand. Hear his story at resound.fm/about

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