Shure 55SH

The Shure 55SH is a professional cardioid dynamic microphone that has been commonly used in broadcast applications since 1939. Designed by Shure, it has been described as an industry standard microphone, "iconic" for its perfect sound and wide adoption in radio, television, and recording studios. From the 1940s until the end of the 20th century, it maintained its popularity in the professional environment. Shure designed the Unidyne transducer in 1939 and then greatly improved it in 1959, based on research and development by Shure engineer Ernie Seeler. 

 Background 
In 1931, Shure and engineer Ralph Glover began developing Shure's first microphone, and the following year the Model 33N two-button carbon microphone was introduced, making Shure one of only four microphone manufacturers in the US. In 1939, Shure introduced the Unidyne Model 55 microphone, which became one of the most recognized microphones in the world.

In 1941, the United States military contracted Shure to supply microphones during World War II, and by the following year, the T-17B was the most widely used microphone by the United States Army and Navy. Shure also manufactured throat microphones, headsets, and oxygen mask, and adopted the United States military standard for all Shure microphones. 

 Gallery 

 Technical specifications 
* Frequency response: 50 to 15,000 hz

* Polarity: cardioid

* Sensitivity (at 1,000 Hz open circuit voltage): -58.0 dBV/Pa (1 Pa = 94 dB SPL)

* Impedance: EIA -150 Ω (270 Ω current)

* Polarity: Positive pressure on the diaphragm produces a positive voltage on pin 2 relative to pin 3

* Connector: 3-pin male XLR

* Switches: on off

* Weight: 0.624 kg

 Awards 

 1943-1946: Army-Navy "E" Award and 3 "E" Stars for Excellence in Production awarded to Shure 

 References 

 Other websites 



 Rose Shure NAMM Oral History Interview (2005)
Category:Audio technology