Set this to roll off around 90 Hz.
If you can, make sure you’re using a wide Q in your equalizer so it’s a smooth transition. You shouldn’t reduce the levels more than -3 dB to 5 dB.
If that doesn’t sound right to you, or sounds piercing, try moving the high shelf to 9 kHz and everything else accordingly.
4-5 kHz is a harmonic frequency and it’s very easy to understand vocals within this range.
You may not even need this step, depending on your recording equipment and atmosphere. If it sounds ok to you, you can skip this step.
These noises are usually in the 5 kHz to 8 kHz range.
