Setting the stage for stereo

In 1939, the year that Shure introduced the Unidyne Microphone, Major Edwin Armstrong invented FM radio and made the first experimental FM broadcast. Two years later, commercial FM broadcasting began in the United States.

In 1972, a significant new chapter in broadcasting history was written in Chicago when the WFMT Fine Arts Station became what is believed to be the first FM radio station in the world to broadcast a live event in four-channel stereo.

To provide the vital mixing capability, WFMT called on Shure, whose M67 Microphone Mixer was considered best suited to the demanding experiment. The scene was the Civic Opera House, home of Chicago’s renowned Lyric Opera Company. It was opening night of the new season, and it is a tradition to broadcast the opening night performance of every opera production. But this year WFMT decided to make a particularly special broadcast. A live broadcast would be the ideal test for the new four-channel stereo matrix encoding system. The nerve center of the broadcast was in a corner of the first balcony of the Civic Opera House, where WFMT engineer Mitchell Heller shared a table with host Norm Pellegrini. Here a console for Shure M67 Professional Microphone Mixers received inputs from eight Shure microphones and directed them to the four stereo channels. There was one M67 Mixer for each channel. A fifth M67 was placed at the desk in combination with a Shure SM53 Microphone, which Mr. Pellegrini used for his commentary. Although only a few hundred persons in the area were able to receive the broadcast in four-channel stereo, it was an important step in the development of the state of the art.

In addition to the Shure mixers and microphones, the station also relied on Shure V-15 Phonograph Cartridges and Shure SME 3009 Series III Tone Arms to play its extensive record collection for broadcast.