An equalizer is a plugin we use in our digital audio workstation to modify the frequency response in our audio. It’s the most basic of all the building blocks to make our voice start sounding professional. We can accentuate parts of our audio, or correct flaws caused by our room. Anytime you start editing a podcast, an EQ will be the first thing we start using, and probably the last thing we’ll adjust. It’s our swiss army knife to fix all sorts of problems that we might run into, so it’s very important we learn to use it correctly.  

For us podcasters, we’re mostly going to be applying EQ to voices. Moreover, we’re trying to make our podcasts sound warm and inviting, not hyperreal or out of this world, like voices on pop songs sound. So this means there are a few fundamental rules we can follow when we break down the areas of the human voice.  

Anytime you start editing a podcast, an EQ will be the first thing you start using, and the last thing you’ll adjust.  

Below 80 Hz is of little use to podcasters. The human voice doesn’t go any lower than this point, so by putting a high pass filter (a filter that “gives a pass” to anything higher than the selected frequency, leaving them unaffected. A low pass filter does the same for anything lower than the selected frequency) at this point can help to clean up the audio by taking away energy from sounds like thumps, bumps and plosives (bursts of air into the mic when saying words with “puh” sounds, like “plosives”). If the high pass filter has different roll off curves, try -12 or -16 dB per octave.

80-120 Hz is where we get the full, rich timbre of voices. This is the fundamental of our voice, the very bottom of our chest. One of the reasons why phone calls sound so off-putting is because they don’t include this frequency, making our voices sound thin and wispy. And also digital and crunchy, but that is another matter. Point being, this range is important to intelligibility and warmth.

200-240 Hz is where we start to get some boominess in voices. Boosting in this area can make our voices sound too heavy or dense, it can be unpleasant. If you’re looking to make a PA announcer effect in your podcast, this is a good frequency to boost, but if you find difficulty balancing the perceived loudness of a male and female podcaster, try making a cut to the male’s voice here.

This EQ does not have a high-pass filter, useful for getting the bassy, “morning radio” sound  

300 Hz-1 kHz is where we’ll hear the most reflections of our voice from the room. If you’re in a large space with lots of hard surfaces, reducing the frequencies in this area can make your audio sound more like it was recorded in a smaller, more intimate environment. It won’t fix everything, but it can definitely start to make your recording seem more “expensive”

2-3 kHz is the area that adds clarity to our voice. These are the frequencies that give shape to the fundamental frequencies of our voice. In fact, if you look at the frequency response of the human ear, you see a bump in the 1-3kHz range, because we’ve evolved to listen for those frequencies of the human voice. Perhaps not surprisingly, a telephone call maxes out at 3.4 kHz as that is the highest frequency you need to ensure intelligibility of the speaker. So if you’ve having difficulty understanding someone in a recording, try boosting in this area, because your listeners’ ears are listening to this range more than others.

5-15 kHz is the area that produces a sibilance. Sibilance is the name we give the extra energy “tuh” and “sss” sounds have. They disproportionately cut through audio recordings and can be very draining on listener’s ears. However, instead of EQing this area, it’s better to use a de-esser.

15 kHz and beyond is the “air” of the track, the part of the voice in pop songs that gives the vocal a sense of space, and it is really lovely when used that way. However, when you listen to your favourite podcasts, you’ll probably notice that there is almost no information in this high end. Professionals don’t seem interested in this very sparkly area of the voice at all. And this is because really high frequencies don’t do well when they are converted into a low bitrate format, like the ones we send podcasts out in. You’ll notice that at 64 kbps, all the high end energy that producers lovingly call “crisp” start to sound “harsh” and “distorted”. So more often than not, especially with less expensive microphones with a boosted high end, we’ll put a multiband compressor over this area to tame the harshness.

At 64 kbps, all the high end energy that producers lovingly call “crisp” start to sound “harsh” and “distorted”

At this point you’re probably noticing that almost all the EQing tips stated thusfar have been about cutting frequencies, rather than boosting. However, almost all the presets you’ll see for dialog EQ will recommend boosting frequencies. So why do we at Podigy try to only cut?  

There is a very good reason for this. Boosting with EQ can also bring up your noise floor and any resonant frequencies found in the room. So your boost to make your voice more intelligible is also boosting the whine of the laptop in the room. By making an effort to cut frequencies we don’t want, and leave the ones we do want relatively untouched, we’re making our sound overall cleaner. Because podcasts are almost never recorded in an acoustically neutral environment, cutting frequencies can make the resulting podcast sound more professional.


Here is an example of an EQ curve with only cuts, used in the podcast at the top of the page, that is a great starting place for a lot of vocals:

Make sure you have an EQ that allows for 7 separate bands (most do). Then, input these settings:


1.
Type: Band
Frequency (Hz): 87.0
Gain (dB): -1.3
Bandwidth (oct): 3.70


2.
Type: Band
Frequency (Hz): 209
Gain (dB): -2.5
Bandwidth (oct): 3.7


3.
Type: Band
Frequency (Hz): 547.7
Gain (dB): -5.4
Bandwidth (oct): 3.7


4.
Type: Band
Frequency (Hz): 1495.0
Gain (dB): -5.4
Bandwidth (oct): 2


5.
Type: Band
Frequency (Hz): 3256.0
Gain (dB): -2.7
Bandwidth (oct): 3.7


6.
Type: Band
Frequency (Hz): 7400.0
Gain (dB): -1.3
Bandwidth (oct): 3.7


7.
Type: High Pass
Frequency (Hz): 70
Gain (dB): 0.0
Bandwidth (oct): 1.0



Now that we have a handle on how to use an EQ, lets talk about where to put it in our FX chain. Typically, for podcasts, we’ll want to place it after denoising elements, but before compressors. This way we aren’t inadvertently altering the loudness of our tracks, ensuring that they are all conforming to loudness standards.

There you have it! This should be enough to get you up and running in your podcast editing endevours with a new sense of how EQ works. If you want to see how to use EQ in conjunction with other effects, check out our Complete Guide to Podcast Editing.