Irving M. Fried

Ever since the first electrical loudspeaker—a glorified headphone with a horn on it—was outmoded by the balanced-armature cone speaker, paper has been the standard diaphragm material for speakers reproducing low frequencies. The Rice-Kellogg moving-coil transducer replaced the balanced-armature driving system in 1925, but the paper cone remained. And although many improvements have since been made, were no more major changes in loudspeaker design for over 30 years!