Description:
A Western Electric model 630-A microphone, known as an "8 Ball" for its spherical housing. It is a moving coil-type microphone, introduced in 1931.
The metal body of the microphone is spherical with circular openings on two opposite sides, one to admit sound and the other to accommodate output connections. Inside the spherical housing are a moving coil and a condenser.
The sound is admitted through a series of circular openings, arranged in a circular pattern of perforations, which are covered by a removable acoustic baffle assembly. The baffle is a flat, disc-shaped circular screen, designed to enhance the non-directional acoustic characteristics of the device. The baffle was designed by Bell Laboratories.
A circular well in the microphone body houses a TypeA Cannon XLR 3-pin plug that connects the microphone to the outputs.