Irregardless of you being bored, CD players have been oversampling for a very long time now and grick wall filters are ancient history, if ever used.

And the need for ultrasonics is just plain silly, regardless where you sit day in and day out. Research has shown otherwise, regardless of the content of instruments above 20kHz as it is well below the threshold of detection, for one.

You would do well to read some of the research on ultrasonics, what effect it has or doesn't in heariong and perception, Boyk not withstanding as he has zero evidence for audibility by anyone. Maybe you can contact J. Stewar of Meridian, or Homlinson closer to home. Or, the ASE paper on audibility of ultrasonics.