Cut hakl spectrum

I don’t understand sound adjustments at all.
He just needs to do this once. See Fig. 1 and Fig. 2. Somehow to always cut half of the spectrum. At the top and bottom. At the bottom, the top. What command or effect will it do to me?
Thank you.
Windows 10.0.19044.1466]
3.1.3 Audacity

Somehow to always cut half of the spectrum.

You want to do that???

Effect → Distortion → Rectifier Distortion. Set it to 100%.

Note that this is full-wave rectification (the negative half of the waveform is flipped to positive). Half-wave rectification would throw-away the negative half but that option is not built-into the effect.

If you want it to go negative you can use the Invert effect. If you just want to invert the right channel click the drop-down arrow and Split Stereo Track so you can edit/process one side at a time.

of the spectrum.

Actually, that’s the “waveform” with amplitude on the vertical scale and time on the horizontal scale. It’s the most common way of visualizing sound waves and it’s the way digital audio is stored with each sample representing the amplitude at one instant in-time.

A “spectrum” also shows amplitude on the vertical scale but frequency on the horizontal. It usually shows just a short selection of the audio rather combining all of the frequencies for the whole file.

Then there is a “spectrogram” which shows frequency vertically, time horizontally, with the amplitude (“intensity”) of each frequency shown as color.

Half wave rectification can be done with this command in the Nyquist Prompt:

(s-max 0 *track*)

or for the bottom half:

(s-min 0 *track*)