Shure SM87A Condensor Microphone
The Shure SM87 now features a new design and has been renamed the SM87A. In response to user requests, Shure has redesigned this microphone by just slightly thickening the handle for a more comfortable feel. In addition, the SM87A now includes the A25D break-resistant swivel adapter. A favorite choice of the world's top entertainers, the SM87A condenser microphone features a smooth frequency response that's specifically tailored for warm, rich, vocal reproduction.
Power
The SM87A requires phantom power. This may be supplied to the microphone from an external power supply (such as the Shure model PS1A) or directly from preamplifiers, mixers, or consoles with built-in phantom power. Suitable sources should provide 11 to 52 Vdc phantom voltage.
Proximity Effect
Unidirectional microphones such as the SM87A progressively boost bass frequencies by 10 to 15 dB at 100 Hz when the microphone is at a distance of about 6 mm (1/4 in.) from the sound source. This phenomenon, known as proximity effect, can be used to create a warmer, more powerful sound. To prevent explosive low frequency sound during close-up use, the SM87A bass response gradually rolls off. This provides greater control and helps the user take advantage of proximity effect.
Wind Noise
The SM87A has an integral wind and pop filter which provides excellent protection against most wind and breath noise. Under adverse conditions, such as high winds or close proximity to a "problem" vocalist, the optional foam windscreen can be used.
Impedance
A minimum load impedance of 800 ohms should be used for maximum signal handling and minimum distortion. The load may be as low as 150 ohms, but a reduction in output signal strength and output clipping level will result.