Objective testing of pick-ups and loudspeakers

The paper describes some of the analytical and experimental techniques used in an objective assessment of the performance of the transducers in a gramophone reproduction system, namely the pick-up and loudspeaker. It is shown that analysis by dynamical analogies provides a means whereby a general mathematical solution for their performance may be reached. Apparatus used to determine the steady state and transient response is described and examples of typical tests are given to show the value of these techniques. Details are included of methods used to indicate and record, together with other relevant information, the mechanical vibrations set up in these transducers.