Oktava MD-66A

The Oktava MD-66A, manufactured at Oktava's factory in Tula, USSR, was introduced in the mid-1970s as a robust dynamic microphone for voice communication in noisy environments, control rooms, and industrial applications such as air traffic control.

Unlike the more refined studio microphones in Oktava’s catalog, this model prioritised speech intelligibility over neutral sound reproduction, with a limited frequency range and noise-cancelling design tailored for use in high-background-noise settings.

Marketed as a microphone specifically for speech and official communications, the Oktava MD-66A was designed with features aimed at improving vocal intelligibility in noisy environments. Its frequency response is shaped with a gentle low- and mid-frequency attenuation and a noticeable boost above approximately 4 kHz, improving clarity of speech.

To reduce background noise, the microphone incorporates rear ports behind the diaphragm, enabling acoustic phase cancellation. Ambient noise arriving equally at both the front and rear is partially cancelled out, therefore increasing directional focus on the speaker. Additionally, a narrow high-frequency polar response reduces the pickup of off-axis high frequency information.

These features made the MD-66A particularly well-suited for use in high-noise environments such as control rooms and industrial settings, where capturing close mic'd speech and rejecting background noise rejection is critical.

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