These ultrasonic playback things are depending on specific interference patterns materializing at certain spots. The design of the signals, shape of the space,

These ultrasonic playback things are depending on specific interference patterns materializing at certain spots. The design of the signals, shape of the space, arrangement and characteristics of the playback devices all need to be seriously tuned for this. You're not experiencing these ultrasonics with headphones. You're not going to faithfully recreate some ultrasonic interference pattern in a random room with a pair of tower speakers placed in any arrangement. If anything, you're more likely to just make extra noise that wouldn't have been there originally from those interference patterns happening haphazardly and chaotically, coupled with the fact the vast majority of audio gear isn't designed to reproduce ultrasoincs (they're often specifically made to try and not generate them!) And even then, by recording in the room with the instrument, you are capturing the resulting ultrasonic interference that you could have experienced if you were there.