How To Use Equalization Effect In Audacity For Voiceover

Audacity Equalization Effect Plugin Basics

Always set Audacity to make a copy to work with leaving the original file untouched. Being neurotic, I make copies of the original and save in a different folder or upload to Drive.
 
Some “experts” suggest you use compression before equalization. I would remove high end and subsonic noise first, then compress, then EQ.
 
If you start reading about mastering by Pro’s you will go mad. You can make a mediocre recording sound fabulous and no one will notice it’s not perfect.

Using that happy paradigm: 

An EQ filter allows us to boost  or lower the gain (audio level) of a range of frequencies above and below the freq we select without boosting everything.. You are adjusting a range. The numbers that run across the bottom of the Equalizer Show the frequencies low to high going left to right. In graphic mode we use sliders. 

 It's not the same as when we adjust the volume of audio which adjusts all frequencies equally.

  • Frequency. This sets the center of the range of frequencies we want adjusted.
  • Gain. This determines the amount of change. Positive numbers boost the gain in that range of frequencies, while negative numbers reduce the gain in that range. What the sliders change, boosts+ or reduces-.
  • Q/Width. This determines the width of the range of frequencies we want to adjust. Higher numbers create narrow ranges. When adjusting values for a voice, the default setting of 2 is good.

Sample EQ Settings

We're going to use graphic mode

  • Men: Add 3-5 dB around 180 – 200 Hz.  for warmth
  • All: Add 3-5 dB around 315 Hz.for warmth
  • Men: Add 4-6 dB around 3,000 Hz clarity
  • Women: Add 4-6 dB around 4,000 Hz  clarity
Reduce low-frequency if the voice sounds “rumbly” and muffled.
Reduce highest frequencies and lowest to reduce noise if necessary, but watch out for creating a sound that's artificial.
Cutting at around 80-130 Hz can clean things up 
Noise is not a single frequency. Noise spans the entire range of human hearing. This means that you can’t use a simple EQ to remove noise, unless it is a very deep rumble or high hiss. Instead, you use the noise reduction plugin.It may be tempting to try to reduce AC mains hum with EQ but those sounds have harmonics which are tough to get without damaging the quality. 
   
Other Tips

1. Use a High Pass Filter to Cut Everything Below 80Hz
This is a common practice and something that you can do to improve any voice over. Anything below this frequency will be low end rumble and noise. Remove it, and it will instantly clean up your voice over.
Try going even higher, especially on a female voice. If your voice recording is sounding a bit too bass heavy, cutting everything below 100Hz will really help with intelligibility.

2. Cut 100-300 Hz to Add Clarity
Similar to the last tip, cutting the bass will improve clarity. On the other hand, if the voice sounds a bit thin, try boosting somewhere in this frequency range.

3. Cut 300-400 Hz if the Voice Sounds ‘Muddy’
This is a problematic frequency range for most recordings—particularly in music. If the voice sounds a too muddy, try cutting somewhere around this area.

4. A Wide Boost Between 2-6 kHz Can Improve Clarity
If cutting some of the bass around 100-300Hz doesn’t add enough clarity, try a gentle boost across this frequency range.
Be careful of exaggerating the S sounds of the voice though, which leads me on to…

5. Cut Around 3-5 kHz if the Voice Sounds too Sibilant
Be wary of this frequency range when boosting. Boosting too much at these frequencies can make the voice sound highly sibilant and add too much sizzle.

Hey  Generally if a male voice is sibilant it will tend to be in the 3-5k Hz range. If a female voice is sibilant it will tend to be in the 5-8k Hz range

if the quiet parts are difficult to understand, you can apply an EQ boost in the 2-5k Hz range after the compressor to aid diction.

Subsonic Noise

Subsonic or low-band noise can enter your recorded audio through physical vibrations during the recording or noise from HVAC, fans etc.

Frequencies below 20 Hz are "subsonic" because the human ear is unable to perceive it as recognisable sound.  First remove any DC offset in the recording using the Normalization plugin.

To remove subsonics from your track you may filter it with:

  • Audacity's built in Equalizer under the Effect menu 
  • Audacity's built-in High Pass Filter under the same menu - set the cut-off frequency to around 25 Hz. You can repeat this same effect a couple of times if a sharper cut-off slope is desired.
  • This Nyquist plug-in subsonic

After removing subsonic noise re-normalize your audio. It will be louder with more definition in the bass.