Shure 55SH Series II Unidyne Vocal Microphone:
An instant success, the original Unidyne set a new standard of high quality audio combined with discrimination against unwanted sounds. True to Bauer’s design, the directional response was more predictable and better behaved than its predecessors, so it offered a new ability to control feedback and reduce ambient noise pickup. In addition, its size was small compared to competitive offerings, making it popular with singers, entertainers, and public speakers.
During the years between 1939 and 1946, the Unidyne changed very little. Variations of the original design included the
1940 introduction of a separate broadcast version (Model 555), which had an improved vibrational isolation mount. A radio station call letter plate that t on thetop of the microphone was sold separately as an accessory.
By 1947, the broadcast version had become Model 556, and the three 55 models with different impedances were replaced with one single model, equipped with a multi-impedance selector switch located under the case at the
rear. Changes were in the of ng at the end of the decade; however, as Shure prepared to deliver yet another breakthrough.
In the 1950s, Shure created a print ad for trade publications that illustrated the industry dominance that the Unidyne held around the globe. It was titled “Photographed With More Celebrities the World Over...Than Any Other Microphone.” The subhead read “The Microphone That Needs No Name.” The ad featured a large photo of the Unidyne, but neither the name nor model of the microphone appeared at all. The objective of this ad was to demonstrate how popular the Unidyne had become. It was a microphone that needed no name or introduction. It was recognized everywhere.