I'm a headphone enthusiast, and once I tried to open up my headphones to see how much they move when I play my music.
However, I was really surprised to see that the sounds that I could "feel" actually came from a driver that didn't have any visible motion at all! The only way I could see even the smallest motions was by turning the volume up to extremely high levels that I would never listen to.
I tried to use the calculator I found here to calculate the motion that my headphones would make, and the results I got seemed to make sense, but this calculator was made for large speakers, not small headphones.
Could anyone tell me if this calculator should scale down to a headphone level (45 mm)? If not, what is an estimate for how much motion a headphone driver should be making at moderate volumes in terms of mm traveled?