Western Electric 618 (c.1932)

The Western Electric 618A is a dynamic moving-coil microphone introduced around 1932. EQ Magazine (May 1997, p.28) described it as "a high-end mic for its day, this rugged model has stood the test of time." It cost under $100 new. The 618A was a nondirectional (omni) microphone with a frequency response of 35 Hz to 10,000 Hz. Its output was rated at −84 dB relative to a zero level of 6 milliwatts for normal conversational speech at a distance of three feet.

Sound & Communication noted that the 618‑A was considered an omni mic, but it became quite directional in the high‑frequency range. The same source places it in auditorium and projection room communications systems. Western Electric followed the 618A with later dynamic models such as the 630A (the "Eight‑Ball Mic"), which extended flat omnidirectional response out to 15 kHz.

Circuit‑level details, exact production years, and broader historical context for the 618 are thin in surviving consumer literature.