Shure 545SD Classic Unidyne Instrument Microphone

Dynamic Cardioid Microphone with On-Off Switch, Dual Impedance

The predecessor to the SM57, The 545SD Classic Unidyne Instrument Microphone is a dual-impedance, unidirectional, dynamic microphone.

Shipped connected for low-impedance operation, the 545SD features a silent magnetic reed on/off switch with lock-on option. A favorite for instrument pickup and recording, the 545SD can also be used on lecterns in public address systems.

Features:

• Exceptionally uniform cardioid pattern minimizes feedback
• Selectable dual-impedance operation
• Silent magnetic reed on/off switch with lock option
• Cardioid, dynamic
• Frequency response: 50 to 15,000 Hz

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. To change impedance, see sections on lmpedance Selection and Connections in User Guide.
• Output Level (at 1,000 Hz)
  LOW: Open Circuit Voltage* -58.0 dB (1.3 mV)
  HIGH: Open Circuit Voltage* -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: See User Guide
• Net Weight (less cable): 255 grams (9 oz)