If the rear housing material is hard:
If the rear housing material is hard, the material of the housing does not deform due to the pressure of the air inside the rear housing when the diaphragm moves, so the air rebounds quickly and sharply.
As a result, the diaphragm moves quickly and finely. This kind of diaphragm movement makes it easier to produce tight, high-resolution, clear sounds with a fast attack and precise contours.
