As well as that fundamental note, it has overtones. Rather than a volume fader, which would allow us to adjust the overall volume, an equalizer allows us to just turn up or turn down individual frequencies and individual elements of that sound.Įvery instrument has a fundamental note. By using a shelf instead of a low pass filter, the volume is never rolled off to nothing.So, what is EQing? An equalizer is simply a tool that lets you adjust the volume of the individual frequencies within an audio source. Sounds over 12000 Hz tend to consist of hiss and other unwanted sounds, so the volume in that range can be lowered. A very slight boost here can often add brightness and 'air'. This is the band that holds the overtones, that really define the timbre of a sound. For vocals, you might want to lower this area a tiny bit. Too much fundamental can make the sound heavy and 'boxy', while too little relative to the overtones can make the sound thin and ungrounded. The fundamental frequency of most instruments fall in this range. Combining these two low-end filters creates a softer, more natural sounding fall-off.

This creates a lower-volume 'shelf', instead of continuing to reduce the volume per octave. This filter reduces the volume of very low-pitch sounds, but only by a set amount. Sounds below 75 Hz tend to be environmental noise, mic fumblings, and mouth noises by rolling it off at a rate of 18 dB per octave, these unwanted noises are reduced, if not eliminated. HP (high pass) flat 75 Hz 18 or 24 dB/OCT.

Equalizer for audacity