RCA Type 44

Dr. Harry F. Olson began working for RCA Laboratories, where he developed ribbon microphones, first with field coils and then with permanent magnets, resulting in the first ribbon microphones with bi-directional pickup pattern, the RCA Photophone PB-17 and PB-31, introduced in 1931.

[2] A smaller and lower-priced version of the uni-directional Type 77-A, the 44-A's smooth sound and defined pattern control reduced the effect of reverberation on soundstages and offered higher gain-before-feedback in live sound applications, making it a staple of the audio recording and broadcasting industries.

The 44-BX has the ribbon mounted further towards the back giving it a smaller figure 8 pickup pattern on the rear side.

Jon R. Sank joined RCA's acoustical laboratory in 1957, and designed the BK11, a successor to the Type 44.

AEA continues to manufacture recreations of classic RCA designs, as well as new updated variations.

RCA Type 44-BX ribbon microphone from 1940 used by CBS
Frank Sinatra with an RCA Type 44 microphone on CBS Radio in 1944