Question for mechanism:
The volume of the resonant chamber: The general problem of the consuming products is that the resonant chambers are not big enough. We can only try to find space to enlarge the volume of the resonant chamber.

Sound Hole: Must be more than 1/8 of the diaphragm's area at least.

Airtight: The front and back sound fields of the speaker should be separated to avoid neutralization.

Shock absorber: When a speaker works the vibration will also happen at the same time. In order to reduce interference, it will do good to have some material between speaker and case to absorb the shock.

Mounting: The speakers are usually fixed on the case. Firmly fixed is important especially for the iron housing or the large size to avoid separating in the drop test.