RECENT ADVANCES IN WAX RECORDING 



161 



day recorder is a highly developed apparatus based on extensive 

 experimental as well as theoretical studies. A diagrammatic view is 

 given in Fig. 1.^ Recorders which have been supplied by the Western 

 Electric Company have been designed to operate over a range of 

 frequencies from 30 to 5,500 cycles. A typical frequency characteristic 



Fig. 1 — Diagrammatic view of the electromechanical recorder. 



is shown in Fig. 2. The device operates in linear fashion over the 



range of amplitudes involved in speech and music. As is seen, the 



response falls off below about 250 cycles. This falling characteristic 



is necessary in order that the maximum loudness be obtained from a 



record for a given spacing between grooves without cutting over 



2 "High Quality Recording and Reproducing of Music and Speech," by J. P. 

 Maxfield and H. C. Harrison, presented at 14th Midwinter Convention of the 

 American Institute of Electrical Engineers, New York, N. Y.,^Feb., 1926. 



