Audio Engineering

Loudspeakers 681

Numerically, for Ka , l :

R a c ohms

Ma

mR 0

m kg.





15

267

4

(^30)

./

.

ρ

ρ

It will be seen that the reactive component behaves as a mass loading on the diaphragm
and is a function of diaphragm area only.

F

Rm1

Rm2

Cm1

Mm1

Figure 23.4 : Impedance analogue of Figure 23.3.

2

1

 5

 2

 1

 1  2 512 510

 05

 02

 01

Ka 2 a

Zm

a^20 C

Figure 23.3 : Air load on a plane piston; mechanical impedance ref.; driving point.