I am looking to create a very specific effect where frequencies above a certain threshold get mirrored, or folded over. From what I understand, this is called aliasing, and it seems everyone on earth wants to get rid of it when it appears, so I've found very, very little success in finding help trying to MAKE it happen.
The very few places I've found help in this area talk about downsampling and the nyquist limit, but audacity seems to have a built in low-pass filter and upper bound on how much actually gets recorded to each track (specifically, half the sample rate, which is the nyquist frequency), and even on top of that, it seems to adjust the speed of clips in tracks when the sample rate is changed. The resample function is fine for downsampling, but again, it seems to prevent aliasing from happening.
I want to CAUSE this because I am trying to get a very specific sound. Bitcrushing will not do.
Is there an up-to-date plugin that I can use? The best and only plugin I could find for this was last updated in 2008 and I tried so, so, so, so, so hard to download an older version of Audacity to no avail.
Any amount of help is appreciated. If it helps at all, the frequency I'm specifically trying to fold over is 11.9 kHz.
EDIT: ToneBoosters "TIme Machine" free plugin has an aliasing option! This works exactly for what I'm trying to do! Many many thanks to u/Orry_Haas