This type of transducer occurs at a junction point between the mechanical and acoustical parts of an analogous circuit. An example is the plane at which a loudspeaker diaphragm acts against the air. This transducer may also be characterized by four
terminals. At two of the terminals, forces and velocities can be measured. At the other two, pressures and volume velocities can be measured. The basic equations applicable to the mechanoacoustic transducer are
The analogous symbols for this type of transducer are given at the bottom of
Table 3.3 (page 70). They are seen to lead directly to Eq. (
3.43).