For the first 6 chapters, let’s look at some more typical points about EQ and vocals, starting with a generalization of important frequencies.
In the lows, you’ll find the vocal’s fundamental frequency, between about 100 to 300Hz. Vowel pronunciation will be at about 500Hz, nasal tones between 750 - 1300Hz, presence at 2 - 3.5kHz, sibilance between 5-10kHz, and air or the highest frequencies of the vocal between 12 - 30kHz.
Let’s affect these areas to hear how they collectively affect a vocal.
If our fundamental is between 100 to 300Hz give or take, then we can use a high-pass filter to attenuate everything up to that fundamental. What's more, we can make this attenuation sound natural by using a 6dB per octave slope, to more gradually attenuate these low frequencies.
Or, we can use a slope of 18dB per octave or higher to create a more aggressive cut - which will be more accurate, but less natural sounding.
Let’s compare a natural-sounding high-pass and a more aggressive one.
Typically engineers say to boost around 200Hz or so to make the vocal sound warm, which is true and I say that as well, but, more accurately, boost the fundamental. I like finding the root note of the key the song is in and boosting the fundamental at that note.
Then I’ll find double that frequency, or the 2nd order harmonic and boost that as well. Let’s listen to what in-key low-frequency amplification sounds like.
The low mids, around 500Hz, are typically cut without much thought; however, roughly 500Hz contains a lot of the vowel sounds crucial for pronunciation. For this reason, we can boost them for more intelligibility, or reduce them to almost make the vocalist sound like they’re further away from the mic.
I recommend using the same method we used in the last chapter, and finding a harmonic or the fundamental, but one that’s as close as possible to 500Hz. Let’s boost this frequency and pay attention to the vowels.
One more time, let’s reference the fundamental or root note of the vocal, as we find a frequency near 2kHz to amplify. This is where the vocals presence is, the area that'll help it cut through a busy mix since about 2kHz to 4kHz is where the ear is most sensitive.
By making it in-key we’re increasing the ratio of in-tune to out-of-tune frequencies.
Let’s take a listen and notice how the vocal sticks out.
One thing that’s interesting about vocals, is how nasally and congested tones vary greatly depending on the singer and other variables. Nasal tones aren’t bad, but can reduce clarity, or have an unpleasant effect - my vocals usually have a congested, nasally tone around 800Hz, but for most, it's between 1-1.5kHz.
That said, finding the right frequency to cut will take some careful listening. Let’s pay attention to how reducing this frequency makes the vocal more balanced.
For our last 5 chapters, let’s consider some unconventional ways to process our vocals with EQ.
If your vocal is sounding harsh and has too much of transient response to sit back or blend in with a mix, try a combination of linear phase processing, and dipping high frequencies. Dipping high frequencies is somewhat self-explanatory, but linear-phase will reduce the impact of transients.
Typically this is seen as a bad thing, but it can be used to great effect for this particular purpose. Let’s use a high latency linear phase setting with our high-frequency dip, and notice how the vocal softens.
Usually, when making an air shelf filter, we forget about everything other than air that’s being amplified - primarily unwanted sibilance and maybe unneeded presence. To avoid this, let’s center our band at about 20kHz, increase the Q value, and adjust until the slope hits unity or 0dB at 12kHz.
This way we achieve the air we wanted, without unwanted sibilance.
Let’s take a listen and notice how just the highest frequencies are affected.
Sometimes equalizing other instruments is really equalizing our vocal, since it reduces masking and gives the vocal room to sit. With that in mind, all of the frequencies I boosted on the vocal in earlier chapters, with the exception of the airband, I’ll dip on the instrumental.
This will reduce masking in these key areas. Let’s listen and notice that even though I’m not affecting the vocal, it still becomes easier to perceive.
Earlier we discussed harmonics and how we can amplify them with an EQ; however, the vocal’s harmonics often change since the fundamental changes whenever a new note is sung. With that in mind, we can use a saturator that creates a second-order harmonic, to amplify these changing frequencies.
This way, that harmonic is always being amplified, regardless of the fundamental. Let’s listen, and notice how it has a similar, albeit slightly better effect than equalizing the root note’s harmonic.