CONTENTS ix 



Chapter Page 



4.7 Electrical, Mechanical and Acoustical Systems of Two Degrees of 

 Freedom 60 



4.8 Electrical, Mechanical and Acoustical Systems of Three Degrees 



OF Freedom 61 



4.9 Corrective Networks 62 



A. Introduction 62 



B. Inductance in Shunt with a Line and the Mechanical and Acousti- 

 cal Equivalents 62 



C. Capacitance in Shunt with a Line and the Mechanical and Acousti- 



cal Equivalents 63 



D. Inductance and Capacitance in Series, in Shunt with a Line and the 



Mechanical and Acoustical Equivalents 64 



E. Inductance and Capacitance in Parallel, in Shunt with a Line and 



the Mechanical and Acoustical Equivalents 64 



F. Inductance in Series with a Line and the Mechanical and Acoustical 



Equivalents 65 



G. Capacitance in Series with a Line and the Mechanical and Acousti- 



cal Equivalents 65 



H. Inductance and Capacitance in Series, in Series with a Line and the 



Mechanical and Acoustical Equivalents 67 



I. Inductance and Capacitance in Parallel, in Series with a Line and 



the Mechanical and Acoustical Equivalents 67 



J. Resistance in Series with a Line and the Mechanical and Acoustical 



Equivalents 67 



K. Resistance in Shunt with a Line and the Mechanical and Acoustical 



Equivalents 68 



L. "T" Type Resistance Network and the Mechanical and Acoustical 



Equivalents 69 



M. "ir" Type Resistance Network and the Mechanical and Acoustical 



Equivalents 69 



4.10 Wave Filters 69 



A. Introduction 69 



B. Types of Wave Filters 69 



C. Response Frequency Characteristics of Wave Filters 70 



D. Low Pass Wave Filters 70 



E. High Pass Wave Filters 72 



F. Band Pass Wave Filters 73 



G. Band Ehmination Wave Filters 74 



4.11 Summary of Electrical, Mechanical and Acoustical Analogies 75 



V. ACOUSTICAL ELEMENTS 



5.1 Introduction 77 



5.2 Acoustic Resistance 77 



5.3 Acoustic Impedance of a Tube of Small Diameter 78 



5.4 Acoustic Impedance of a Narrow Slit 78 



