[pajko]

Check out GNU Radio. In contrary to what the name suggests, it's not just for radio, but can be used for doing complex DSP operations. It includes a nice filter design tool, too.

https://www.gnuradio.org/grcon/grcon18/presentations/The_Bri...

https://w7fu.com/audio-oscillator-project/

The best option to install it on Windows is radioconda: https://github.com/ryanvolz/radioconda