Elements of acoustical engineering (1940) Elements of acoustical engineering elementsofacoust00olso Year: 1940 238 MISCELLANEOUS TRANSDUCERS sponse frequency characteristic with record characteristic shown in Fig. is shown in Fig. The output below 1000 cycles is similar to that of the record. Some compensation in the amplifier must be provided to com- pensate for this drooping characteristic. The peak at the low frequencies is due to the resonance of the total mass of the pickup and tone arm W2 with the compliances Cmi and Cm2- Below this resonance frequency the mass reactance due
Elements of acoustical engineering (1940) Elements of acoustical engineering elementsofacoust00olso Year: 1940 238 MISCELLANEOUS TRANSDUCERS sponse frequency characteristic with record characteristic shown in Fig. is shown in Fig. The output below 1000 cycles is similar to that of the record. Some compensation in the amplifier must be provided to com- pensate for this drooping characteristic. The peak at the low frequencies is due to the resonance of the total mass of the pickup and tone arm W2 with the compliances Cmi and Cm2- Below this resonance frequency the mass reactance due to m2 becomes small compared to the impedance of the compliance elements and the output falls off rapidly with decrease in frequency. 3. Dynafnic Pickup. — A dynamic pickup is a phonograph pickup in which the output results from the motion of a conductor in a magnetic Fig. Cross-sectional view and equivalent circuit of the mechanical system of adynamic pickup. In the equivalent circuit: Zmr the mechanical impedance of the record. w?i the mass of the needle and voice coil. Cmi and tmi the compliance and mechanical resis- tance of the suspension system, mi the mass of the pickup and tone arm. /m the force generated by a constant velocity generator. The graph shows the voltage response charac- teristic with the record characteristic of Fig. field. Fig. shows a cross-sectional view of a dynamic pickup^'' for the reproduction of hill and dale records. The principal mechanical im- pedance is due to the mass of the needle and coil. The output of the coil is proportional to the velocity. Therefore, the response characteristic is similar to that of the magnetic pickup. C. Distortion in Record Reproduction^^'^'^. — The recording and repro- ducing of a phonograph record is a complicated process and there are many sources of nonlinear distortion. The record does not present an infinite impedance to the needle. As a consequence, the vibrating system of the pickup i
Size: 2381px × 840px
Photo credit: © Bookworm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: archive, book, drawing, historical, history, illustration, image, page, picture, print, reference, vintage
