Phase Shift in Electroacoustic Transducers

摘要

A complex transfer function is defined which relates the sound pressure at a point on the principal axis of an electroacoustic transducer to the electrical input of the transducer. The argument of this function is composed of a phase function representing phase shift in the transducer, plus a shift proportional to frequency representing travel time. By using an electrical delay line to match the travel time phase shift, the shift in the transducer itself can be measured directly. Typical phase functions for moving-coil and electrostatic loudspeakers are shown and discussed. The effect of transducer phase distortion on correlation functions is discussed, as is the use of the phase measure¬ment in "phasing" a multiple-transducer system.