What does the SM stand for in the SM product line, e.g. SM58?
SM originally meant Studio Microphone. The first SM mics, developed in the 1960s, were aimed at the TV studio market, with a non-reflective finish and no on/off switch. Rock and roll sound engineers discovered the SM58 and SM57 in the late 1960s, and made these models famous worldwide as onstage performance microphones.