Recording Tips: EQ

Continuing on through some basic recording techniques, this installment will focus on some basic equalizer (EQ) functions and how you can use this tool to enhance your recordings. As with the previous discussion on compressors I will focus primarily on the use of EQ for voice and discuss only very general aspects of usage. In it’s basic forms, the EQ has two different styles, graphic and parametric. The graphic EQ is the most basic and where this particular discussion with focus.

The audio that we record is comprised of many different frequencies coming through at different volumes. Equalization allows us to boost (turn up) or cut (turn down) those frequencies individually. Equalization done correctly can enhance your audio by giving it body (low end), warmth (mid range) and brightness (high end). Equalization can also correct minor recording issues such as plosives (sounds generated by bursts of air such as the “P” sound) and sibilance (hissing sounds such as the “S” sound). The EQ will not make the voice sound like someone else’s, but will enhance (good or bad) what is already there. To use a cooking analogy, the EQ is like salt; it can make good food taste great, but if you use too much of it, it will ruin it entirely.

Typically with a graphic EQ there are adjustable parameters for individual frequencies. Each one can be turned up or down to affect the audio. There is typically also a Q control, which determines how narrow or wide frequencies around the selected frequency will be affected. Think of the Q control as a gentle “U” shape with the affected frequency in the middle, the higher the Q control is set the narrower the “U” is, thus affecting fewer frequencies.

In most cases, the goal of the EQ is to be undetected by the listener, therefore cuts are much more friendly in facilitating this. Boosts can very quickly cause a voice to sound unnatural so boosting gently is preferred. You can take a little more liberty with the cuts without creating a too unnatural sound. Below are some general tips for voice equalization:

• Use of a High Pass Filter (HPF) reduces frequencies below the set frequency (this is sometimes called a shelf). This is very handy for use in vocals as most audible speech is below 125 Hz and applying an HPF somewhere below that can instantly remove plosives and rumble created from mic stand movement.
• Use a slightly lower Q setting (around 1.0) for a gentler, less apparent affect.
• Frequencies between 125 Hz – 1 kHz make up the bulk of the human voice; lower frequencies will affect the body of the sound, adding or subtracting richness while the higher frequencies will affect nasal qualities. Frequencies above 1.25 - 5 kHz affect the crispness of a vocal and allow it to cut through other sounds better such as a music bed. Frequencies above 5 kHz affect the brightness quality of a voice sometimes providing a more breathy sound. Too much boost in the higher frequencies will cause the voice to sound thin and brittle.

Not one recording is the same as the next, take time to work with each individual recording and address the uniqueness of the sounds. The EQ is a very easy to use tool and can have a very positive impact on your finished product if used wisely.