Crown PZM20R Pressure Zone Boundary Microphone

Crown PZM20R Pressure Zone Boundary Microphone
The PZM-20R is a Pressure Zone Microphone designed for permanent flush-mounting in tables, lecterns, pulpits, and judicial benches. Its unobtrusive appearance and hemispherical pickup pattern make it ideal for conference table use. The microphone fits into a 4.59-in. (11.659-cm) square hole or in a standard 4.0-in. x 4.0-in. (10.16-cm x10.16-cm) electrical outlet box.

Electronics in the base of the 20R adapt the microphone for phantom powering. No external power-supply interface is required. The microphone plugs directly into a phantom power supply providing 12 to 48 volts. The wide-range frequency response of the20R is emphasized at high frequencies for clarity and articulation. Low frequencies below the voice range are filtered out to reduce rumble.

Three small guard-posts prevent papers from sliding underneath the cantilever arm and altering the frequency response. Like other Pressure Zone Microphones, the 20R utilizes the Pressure Recording Process in which a miniature condenser microphone capsule is arranged very close to a sound-reflecting plate or boundary, The capsule is mounted in the “Pressure Zone” just above the boundary, a region where sound coming directly from the sound source combines in-phase with sound reflected off the boundary. The benefits are a wide, smooth frequency response free of phase interference, excellent clarity and “reach,” a hemispherical polar pattern, and uncolored off-axis response.

SPECIFICATIONS

• Type: Pressure Zone Microphone
• Element: Electret condenser.
• Frequency response (typical): 80 Hz to 20 kHz
• Polar pattern: Hemispherical on an infinite plane.
• Open circuit sensitivity: 7 mV/Pa* (–43 dB re 1 volt/Pa).
• Power sensitivity: –43 dB re 1 mW/Pa. EIA sensitivity –135 dBm.
• Impedance: 240 ohms balanced. Recommended minimum load impedance 1000 ohms.
• Equivalent noise level: 20 dB SPL (0 dB = 0.0002 dyne/cm2), A-weighted.
• S/N rati 74 dB at 94 dB SPL.
• Maximum SPL: 150 dB SPL at the microphone produces 3% THD.
• Polarity: Positive pressure on the diaphragm produces positive voltage on terminal 2 with respect to terminal 3 of the output terminal strip.
• Operating voltage: Phantom power, 12 to 48 volts DC, positive voltage on terminals 2 and 3 with respect to terminal 1 of the output terminal strip.
• Current drain: 1.1 mA.
• Color: Black.
• Connector: Screw terminals. #1 shield, #2 audio inpolarity, #3 audio return.
• Cable: Not Included - use 2-conductor shielded microphone cable.
• Weight: 8.1 ounces (230 grams).
• Optional accessories: Crown PH-1A phantom power supply (single channel, battery or AC adapter powered),
• Crown PH-4B phantom power supply (4 channels, AC powered).