The significant operational difference between the bidirectional and omnidirectional microphone is that
while the omni responds with equal sensitivity to sounds arriving from any and all directions, with a
properly designed single-diaphragm bidirectional microphone, a response null of almost -90dB will oc-
cur at precisely ±90° from the principal pickup axis. Figure-8 shows that this null exists both vertically
and horizontally because a soundwave approaching the microphone along the plane of the diaphragm
will produce equal pressure on both sides of the diaphragm. If there is no difference in pressure on the
