REGULAR COMBINATION OF ACOUSTIC ELEMENTS 

 Combining these equations, we obtain 



^2- Sr 



277 



2^2 



FiZo / 5i + 52 



^^=^4(^)^°^'' + 



S, \ 23-2 

 ..= ..[(^)cosHr-(^)] 



or for simplicity we write 



2Si 



sinh r. 



sinh r, 



{S3) 



PlA 



¥"H 



^1^1 



(34) 



V,= V,C -^D. 



In order to express the propagation in terms of some known func- 

 tions we will first obtain some relations between the impedances of 

 the sections and the ratios of p^lpi and F2/F1. We can write the above 

 equations as 



pi Zi Vi ^0 



where Zi/Si = pi/Vi. Eliminating Zi, we have 



BD - AC= - 1 



p2 V2 _ A Yl — rh 

 Pi Fi ^ Fi ^ 



Pi 



(35) 



as can be seen by multiplying together the above expressions. Solv- 

 ing for the ratio of F2/F1 in terms of p-ilpx, A and C, we have 



Yl = lP 

 Fi P2 



Pi 



C^-1 



- A 



Multiplying both sides by pifp2, we have 



C -^ 

 Px F2_ P2 



Fl p2 p'2 



- A 



