Undetectable very-low frequency sound increases dancing at a live concert
I've been chasing infrasonic ranges in home audio for over 2 decades. You can't "detect" these frequencies in the normal way. You experience them by way of your physical environment being excited by them. <i>Feeling</i> pressure waves move through whatever you are standing/sitting on can add an entire new dimension to the experience.<p>I used to run experiments with friends and family using a 800L ported subwoofer tuned to ~13Hz with a 40Hz cutoff. Not one person would mistake it for being on vs off. Certain content makes these frequencies substantially more obvious. Classical music performed in large concert halls is one surprising candidate outside of Mission Impossible scenes. Being able to "feel" the original auditorium in your listening room is a very cool effect to me.