A PCC (P
is a boundary microphone that uses a cardioid element
mounted perpendicular to the boundary surface. By keeping the element
very small and located very close to the boundary surface, the resulting interference from reflections also occurs at very high frequencies. This same general concept is often applied when measuring loudspeakers or speaker
systems, the measurement mic is place very near a large reflecting boundary surface in order to minimize the effect
bounce' and push the resulting interaction up to frequencies above those being measured.