UNIDYNE III 545SD-LC Dual Impedance Unidirectional Microphone Specifications:

• Type: Dynamic
• Frequency Response: 50 to 15,000 Hz
• Polar Pattern: Cardioid (unidirectional)--uniform with frequency, symmetrical about axis
• Impedance: Dual. Microphone rating impedance is 150 ohms (250 ohms actual) for connection to microphone inputs rated at 19 to 300 ohms and "High" for connection to high-impedance microphone inputs. Wired for low impedance as supplied.
• Output Level (at 1,000 Hz): Open Circuit Voltage*: Low: -58.0 dB (1.3 mV); High: -35.0 dB (17.6 mV)*0 dB = 1 volt per Pascal (1 Pa = 94 dB SPL)
• Polarity: Positive pressure on diaphragm produces positive voltage on pin 2 (with respect to pin 3).
• Switch: Built-in magnetic reed on/off switch with lockplate.
• Cartridge Shock Mount: Internal rubber vibration-isolator
• Swivel Adapter: Positive action, adjustable through 90 degrees from vertical to horizontal, permits easy removal for handheld use, suitable for mounting on stand with 5/8"- 27 thread
• Case: Chrome-plated die casting with ARMO-DUR grille and stainless steel screen
• Dimensions (Length x Diameter): 6-3/16" x 1-1/4" (157 x 32 mm)
• Net Weight (less cable): 9 oz (255 grams)