ABSTRACT
A type of loudspeaker in which a tweeter is mounted concentrically within a woofer, each having its own voice coil. A substantial frequency overlap is desirable between them.
One of the popular cartridges of the high fidelity era, marketed by Zenith ca. 1948. It was a moving iron type, lightweight to give three times as many plays per record without loss of frequency response. A round flat vane was attached to the top of the stylus, with a small coil adjacent to the vane; movements of the vane were transmitted to a connected oscillator.
