In reply to:

Music rarely, if ever, has those kind of low frequencies.



True. My favourite for testing is music with Victor Wooten playing his tenor bass (low A at about 27.5 Hz - Flight of the Cosmic Hippo, for example). I don't listen to much pipe organ, well ok, I don't listen to any pipe organ music so as long as a sub is musical down to 25 Hz, that is good enough for me musically.

I agree that typically only in movies will you experience anything lower.