Audacity Equalization Effect Plugin Basics
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
- 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 highest frequencies and lowest to reduce noise if necessary, but watch out for creating a sound that's artificial.
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.