“No Infrasound” was my name for a high-pass filter, ( a/k/a/ bass roll-off), which removes inaudible infrasound.
For some reason my “No Infrasound” post is off limits at the moment … Improving an old recording - #15 by Trebor
However you can see how to re-create such an equalization here … Help with equalizing audio - #18 by Trebor
“AppData” is a hidden folder in Windows , but you don’t need to make it visible to save an EQ-curve you’ve created , or imported , that can all be done within Audacity’s equalizer, see “Manage Curves” here …
http://manual.audacityteam.org/o/man/equalization.html#manage