High-pass filter (low cut)
An EQ move that rolls off everything below a set frequency, thinning out rumble and boom while leaving the voice intact.
See it
What it is
A high-pass filter lets high frequencies pass and rolls off everything below a chosen corner frequency. Same thing as a 'low cut', just named from the other end. The corner is not a wall: the slope (6, 12, 18, or 24 dB per octave) decides how fast the low end fades out below it.
It is the first move on almost any spoken-word track. Desk thumps, mic-stand bumps, and proximity-effect boom pile up at the bottom, and so does a chunk of the HVAC and traffic (though both of those also reach well up into the voice, so a high-pass thins them rather than removing them). 80 Hz is a starting point, not a rule, and certainly not a rule about the speaker's gender: adult voice fundamentals sit across roughly 80 to 250 Hz and overlap any number you might prescribe. Set it by monitoring this recording. On a full music mix where the low end carries the track, 30 to 40 Hz is the more usual place to start.
Gotcha: set it too high and the voice goes thin and telephone-ish, and the damage is not recoverable by boosting the lows back. Sweep the corner upward until the voice starts losing weight, then back it down a notch. Steep slopes also ring near the corner, so a gentler 12 dB per octave usually sounds more natural than 24.
Ask AI for it
Apply a high-pass (low cut) filter to this dialogue track: start the corner at 80 Hz with a 12 dB per octave slope to thin out HVAC rumble, handling thumps, and proximity-effect boom. Then set the final corner by monitoring this specific recording rather than by any rule of thumb: sweep it upward until the voice starts losing chest weight, then back off. Report the frequency you landed on and why. Keep the voice from sounding thin or telephone-like, and add no other EQ.