Greetings from Blackbird! Here are some points about equalizing vocals, ranging from general to specific.
Why It's Important
Music is a powerful form of communication, and we generally tune into and relate most deeply to the most human instrument - the voice.
Our brains are optimized to receive vocal information and to decode the messages and emotions that it carries. We respond to the tone quality or timbre of a voice, which can carry urgency or tenderness, angst or joy, or any in the full range of emotions.
The sound and understandability of singing, speaking, or rapping are critical to music’s impact. The signal processing that affects timbre most directly is equalization.
Having an understanding of how this process works, what the parameters are, and how to get at them will help you in your mission of helping to deliver an experience. And so - onward!
Understanding the parameters of equalizers will help you to select a tool that works for you. Whether hardware or virtual, equalizers have a number of design and control variables.
They may separate the audible spectrum into only a few bands, or many. They may use tube or solid state amplifiers, or be passive (meaning no amplifier, cut only). They might be inductor-based, like a Pultec. All of these variables represent sonic choices that you can apply.
There are different types of equalizer interface: rotary, graphic, semi-parametric, parametric, etc. Though the controls are different they all have the same effect, which is to alter the tonality through their action (and sometimes through the sound of their amplifiers, including distortion).
Despite the variations, equalizers generally control the same two or three parameters for each frequency band: center frequency, volume change (boost or cut), and if parametric, bandwidth (literally, the width of the band of affected frequencies, labeled “Q”).
1. Find the Frequencies
One of the skills of recording is learning to separate and identify frequencies and frequency bands. Where in the spectrum is there too much, or not enough? Use your experience and knowledge to estimate its frequency range, boost that range by an exaggerated amount, and sweep up and down (usually in the context of the song). When you hear the stuff you like, try a more moderate amount of boost, and when you find stuff you don’t, cut it.
This brings us to a couple of small but useful tricks for Avid’s EQ3:
1. When you’ve boosted a frequency band and swept to find an offending frequency, shift-clicking on it causes it be cut by the same amount.
2. Shift+control-clicking on a band or control solos that band, making it easier to tune your EQ. Try not to use the same EQ’s and settings on every instrument, as you can get frequency loading - too much of the same. High pass filters can be especially useful for removing muddiness. Finally, keep in mind that an EQ is not a synthesizer - it can only boost what’s present in the sound, not generate frequencies that aren’t there.
2. Watch Your Levels
An equalizer is a variable amplifier, and adding gain raises the possibility of distortion. We hear cuts less than we hear boosts, so for these reasons try to learn to think subtractively - turning down the stuff you don’t like, as opposed to boosting what you think you need more of.
I generally equalize after compression, to correct for the potentially dulling effect of a compressor or limiter. Turning up the frequencies you like will drive more of them into a post-EQ compressor, which will then react by turning down more.
3. Mind your Q’s
Equalizers that have a bandwidth or Q control give you the option of affecting a wider or narrower area. Broad-band boost or cut is often referred to as musical or program equalization, while narrow-band cuts are called surgical EQ. The names of these two different techniques and approaches reflects their purpose and applications.
Many well-known equalizers, such as API, are “proportional Q”, meaning that their bandwidth gets narrower with more boost or cut. They sound familiar and can be spectacular. But, if you’re always at high levels of boost things can get peaky, so it is good to be careful.
Speaking of peaks, remember that there are two gain shapes: peaking and shelving. Mid bands are usually peaks, as can be bass and treble - they boost frequencies around the center of a bell-shaped band. Often though some frequency bands (usually the top and bottom) can be made to shelf, meaning extend the boost or cut from the center frequency to the upper or lower limits.
Choose the shape that brings up what you want, without elevating unwanted sound such as rumble or hiss.
4. EQ in Context
A common beginner’s mistake is to adjust the tone of instruments or vocals in solo. Because of the phenomenon of frequency masking, things sound really different by themselves than when they’re competing in a mix with varying levels of sound at different frequencies. So, don’t spend much time making decisions based on a soloed vocal. Listen to it in context, determine what it might need, and address it.
If certain frequency ranges of the vocal aren’t speaking in the mix, rather than boosting them try turning down the instruments that are covering it. Also try reducing the masking frequencies in those instruments, especially in the vocal intelligibility range, roughly 1-4kHZ.
5. Keep a Fresh Approach
Due to the variable and artistic nature of sound recording, I regret to inform you that there is no EQ recipe book. Though it can be interesting to start with a plug-in preset, you must always listen, analyze and experiment, since every sound, context, genre and mix are different. Try to only apply EQ when it’s needed, to avoid such potential side effects as phase shift and distortion.
Also, don’t automatically put EQ on everything - presumably the sounds were recorded with a purpose in mind, and might be fine as they are. Don’t try to fix volume balance problems only with EQ, when the solution might be compression or panning, or just good old turning it up or down!
When well applied, an equalizer is a powerful tool. I hope that you will find this information useful. Happy EQ’ing!
- Mark Rubel