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. The PB-31 was employed by Radio City Music Hall in 1932.^[1]

Also in 1931, RCA introduced the Type 44-A Velocity Microphone.^[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.^[3]

In 1940, RCA updated the Type 44 with improved magnet material to introduce the Type 44-B and Type 44-BX.^[2] The 44-B and BX were both a slightly larger version of the 44-A. The 44-BX has the ribbon mounted further towards the back giving it a smaller figure 8 pickup pattern on the rear side.^[4] The Type 44-B and BX remained in production until its discontinuation in 1957.The RCA 44 was discontinued in 1957.^[4][5]

The RCA Type 44-BX and Type 77-A ribbon microphones were the most popular microphones for recording in the 1930s and 40s. They were popular not only in broadcasting studios, but also on film studio scoring stages, where they were often used to record string sections. Many of the top American scoring stages still use these ribbon microphones today.^[6]