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  • Tom Kelly

15. Equalizing by Octave: The Characteristics of Each Octave Band on the Human Voice.

Could this title sound any more clinical? Geez. Anyways, this is a super exciting episode! Building upon the frequency band listening exercises last week, we are now exploring more subtle and intentional moves when it comes to equalizing vocals for a podcast!

In this episode we look at 10 different octave bands ranging from 32Hz to 16kHz and explore how my voice sounds when we boost each of those frequency by 2 and 4 dB, and when we cut by 2 and 4 dB. While listening to each move made in this episode, I discuss the characteristics of that frequency band and how my voice changes as we manipulate those frequencies.


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Starting off, what is an octave? We discussed it briefly in last week's episode, but an octave is a doubling of a frequency, for example 32Hz and 64Hz, 250Hz and 500Hz, 4kHz and 8Hz. We can also think of this as playing middle C or C4 and C5 on a piano. As you move from left to right on a piano playing all the C keys, the notes get higher in pitch each time by exactly twice the frequency as the C note that came before it.

But what does this have to do with equalizers? EVERYTHING! Kinda...

I use the example of the classic iTunes graphic equalizer in this episode, which we can see just above. The frequencies it allows us to manipulate are octaves. Most modern equalizers give the user full control over what frequency they'd like to manipulate, along with several other parameters, but this is a good place to start.

This episode places 100% emphasis on the listening exercises within, so it's hard to write about what we're hearing in this episode, but we can revisit some concepts from last week. These octaves fit within several different frequency bands. Each band contains some unique characteristics within. Here are some of the key takeaways heard through the episode.


Sub Bass (20 - 60 Hz)

also calls "subs"

This frequency range holds little to no information in most vocalists. It's common to cut this frequency range entirely with a "high pass filter", which is sometimes also called a "low cut filter".

Bass (60Hz - 250 Hz)

also called "lows"

This extremely important band holds the secret to life within. This is where almost all of the warmth and thickness of the human voice lies, in both men and women., It contains the most power, along with the fundamental frequencies of our voices. Basically, this is where the heart of our voice lives. Without a proper representation of this frequency range, we sound like a phone call or a recording: dull, lifeless, and uninspiring.

Low Midrange (250 Hz - 500 Hz)

also called "low mids"

This frequency range often contains a lot of "boxiness" and can often contain a bit of what is called "mud". Along with the high end of the bass range, an overwhelming amount of 250-500Hz will result in an undefined and washed out sound. I usually end up cutting QUITE a bit of 350Hz and 500Hz out of most voices, men and women. However, cutting too widely in this frequency range will result in a dull and very unnatural sound.

Midrange (500 Hz - 2,000 Hz)

also called "mids"

I'd almost like to break this band into several smaller ones, because it's such an important frequency range. Most of the intelligibility of the human voice lies in this range, as well as a lot of unpleasant and grating sounds.

I like to make sure 750-850Hz is REALLY tight in voice over, as this is the range that is most accurately replicated by low quality speakers and headphones.

However, the 1kHz range holds a lot of displeasing nasalness and most recordings (voice, snare drums, electric guitar, etc) will be better off with a slight cut in this range. Not too much, as things will start sounding unnatural, but a little less nasal never hurt anything.

Upper Midrange (2,000Hz - 4,000 Hz)

also called "upper mids" or "high mids"

If we remember last week's blog post, we know that the human ear is tuned incredibly well to this frequency range. For that reason, we want to make sure it's tamed properly. We're going to hear a lot of bite in this range, and if we're not careful, a lot of the upper mids can cause fatigue when listening for a long time. This is true to most other frequencies above 2kHz, but our ears hear this range with much more intensity than all others.

Lower Treble (4,000 Hz - 6,000 Hz)

also called "presence"

This band is one that accounts for the depth of a signal. It's called the "presence" range because we can attenuate or cut out a lot of this range to make a sound feel distant, and the more the range is represented, the closer it will appear. We need to be careful that we're also removing the sibilance that lives in this range!

Highs (6,000 Hz - 20,000Hz)

also called "air" for 12kHz - 20,000 kHz

When an audio file is compressed to a smaller size, or you are recording your podcast through a VOIP recording platform, Skype, Zoom, Zencaster, etc, this range is the first to go. It's the difference between a studio quality recording and either an amateur recording or a low quality file, such as most podcast mp3s. This is a very wide frequency range that holds many different characteristics within it, but crisp highs are typically sought after in most audio mediums. It gives the audio a sparkle that feels modern and exciting. However, a lot of unnecessary "air" also lives in the very high highs, so we want to tame those in most of our recordings as well! It can be fatiguing on the ears and doesn't contribute too terribly much to the sound once we pass 14-15kHz.


Again, just listen to the episode. A podcast is worth 1,000 written words or whatever the saying is.

BUT, here's something you don't get in the podcast...

Above is a visual of my equalizer working in real time to give you the voice you hear on the show. The last 5 minuets of the episode is me running through the moves I make on my EQ and I present them one at a time so you can hear how these subtle differences add up to give a much more pleasing sound, free of low end build up, grating highs, or flubby mids. While these settings work for me (I think), they probably won't work for you. But feel free to copy my settings and apply them to your own voice.


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My Signal Chain


Audio Interface: Apogee Ensemble

Microphone: Shure SM7b

Studio Monitors: Yamaha HS7


IzoTope RX6 Mouth De-Click

IzoTope RX6 Voice De-Noise

FabFilter ProQ3

Waves Vocal

Rider Waves CLA2A

Waves L2 Limiter

Waves WLM Meter

Waves Durrough Meter

*most of these links are affiliate links

Midroll Song: Road Trip by Joakim Karud

Closing Song: Smile by Joakim Karud

For more info, or to ask any questions, check out my website and reach out to



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