Strict Cuttof

I have an audio signal

I want to cutoff everything below 100 hertz to 0 volume

I want everything over 100 hertz 100 percent volume

I want no transition in-between, just strict cutoff. How can this be done?

I’m betting you can’t do that. There’s always going to be a transition where fractional frequencies get through. Or you can get close enough, but the filters will take forever to work. Vicious filters like that also come with signal damage. 100Hz and up is not going to come out perfect. There is going to be some signal distortion.

What are you trying to do? There may be an alternate way to do it.

Koz

It can’t be done, it’s impossible, but you can get quite close to that with these settings in the Equalization effect (below). This will give around 65 dB attenuation at 80 Hz and -1 dB attenuation at 104 Hz.