Clean up your audio with surgical EQ

The odd sounds

Most recording spaces show certain frequency anomalies in the form of resonances, standing waves, vents, electrical hisses and hums and background noises.

Maybe the anomalies were not noticed during reccording, or perhaps it was impossible to remove them on site. But they will probably show up in mixing or post-production. Luckily there are tools well suited to address these problems.

The problem solvers

Precision surgical EQ’s with multiple overlapping bands can be used to identify and remove the frequencies. One of the first and still respected surgical EQs is the Q10 from Israeli plug-in developer Waves. But any EQ with multiple overlapping bands can do the job also.

Isolating and removing exaggerated frequencies

Start with a single band. Use a very narrow Q (Higher number = More narrow). Boost the band as much as possible (e.g. +18db). Sweep the frequency of the band until you hear a very amplified frequency with a ringing sound. Now turn the boost into a deep cut (e.g. -18db) to remove that frequency. With a very narrow Q, you won’t affect nearby frequencies too much.

Choose a new single band, and repeat the process until there are no more exaggerated frequencies to find.

It is useful to add a spectrum analyzer both before and after the EQ, to verify your decisions.