On the production line in the factory, engineers
and staffs usually do not know how to distinguish the polarity of
the microphone. Sometimes the R & D engineers confuse with the
directional of the microphone; here are some features we can distinguish
by the appearance:
The polarity of microphone: the negative pole need to be connected
with the outer casing, therefore we can differentiate the polarity
from the solder.
The directional of microphone: the unidirectional and the noise
canceling microphone have vents at the bottom; oppositely, the omnidirectional
microphone is completely sealed.
Regarding the back/ foil type, and the capacitor, we have to take
apart the microphone to tell the differences.
In the case of the sensitivity, using the apparatus to test is the