AKG PZM30 D High-Performance Hemispherical Boundary Layer MicrophoneThe PZM30 D from AKG is a high performance hemispherical boundary layer microphone is a pressure zone microphone designed for professional recording, sound reinforcement and broadcasting. The capsule is mounted in the "pressure zone", an area where direct sound and reflected sound are in phase, which provides a 6 dB higher sensitivity. Two selectable frequency responses (flat rising) provide greater flexibility in mic placement and sonic character.