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.
Feature.
Exceptionally uniform cardioid pattern minimizes feedback in PA applications
Selectable dual-impedance operation
Silent magnetic reed on/off switch with lock-on option
Lavalier version available for use as a lectern microphone with A25D adapter, or as handheld microphone
Specs.
Transducer Dynamic
Polar Pattern Cardioid
Frequency Response 50 Hz – 15 kHz
Maximum Input Sound Level not specified by manufacturer
Power Requirements None Dynamic, Requires No Phantom or Battery Power
Output Impedance 150 Ohms (250 Ohms actual) for Connection to Microphone Inputs Rated at 75 to 300 Ohms
