Is the KSM8 the first Shure unidirectional moving coil microphone with controlled/reduced proximity effect? It is not; that honor goes to the Model SM53 introduced in the early 1970s.
Note the “porthole” openings near the XLR connector. By positioning these rear-entry acoustical ports far away from the mic element, proximity effect is reduced. Electro-Voice used a similar principle for its “Variable-D” microphones. Soon after the SM53 was introduced, the model SM54 debuted with the sole difference being a larger grille to improve resistance to plosives [P-popping] and wind noise.
The SM53/54 featured a two-position bass attenuation [reduction] switch: FLAT or ROLL-OFF. When engaged, the bass roll-off started at 800 Hz and was 8 dB down by 100 Hz. The switch was mounted slightly below the handle surface so it would not be accidentally activated by the performer.
From the 1973 catalog description: The SM53 and SM54 are the most versatile studio-quality microphones in the Shure Professional Products line, combining superb response, excellent noise rejection, and outstanding adaptability to a wide variety of assignments in recording, broadcasting, and high-quality sound reinforcement.
The SM53 was a modest success. Notable users were Ray Charles, Johnny Cash, Elvis Presley, and Frank Sinatra. The mic was also employed for a U.S. television game show, “Super Password.”
Performers and sound engineers, however, overwhelmingly preferred the Unidyne III SM58 for its sound, appearance, and feel. The phenomenal ascendancy of the SM58 led to the demise of Shure’s first controlled proximity effect microphone. By 1985, the SM53 and the SM54 were discontinued.
Related information: Frank Sinatra with SM53
Arcana – mysterious or specialized knowledge
The Shure A53M vibration isolation mount was developed to use with the SM53, thus the “53” in the model number. The A53M is a current accessory and compatible with any microphone having a handle diameter of 0.75 inch, such as the SM81.
This unique mount was developed by Shure engineer, Gerry Plice, and its U.S. Patent 3,653,627 was issued April 4, 1972. The patent avers: Apparatus for shock-mounting a microphone comprising of a compact, resilient mounting member defining a socket adapted to receive a microphone body and means for supporting the mounting member in a desired position. The mounting member defines an enclosed space encircling the socket that is preferably filled with a fluid, such as a liquid or pressurized gas. The action of the shock mount can be modified by the selection of different viscosity gases or liquids, or by the addition of foam to affect viscous damping and thereby permit tuning of the apparatus for a particular application.
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The industrial design of the SM53 received a patent in 1970.
