3.7. Examples of transducer calculations
Example 3.6. An ideal moving-coil loudspeaker produces 2 W of acoustic power into an acoustic load of 4 × 104 N s/m5 when driven from an amplifier with a constant voltage output of 1.0 V rms. The area of the diaphragm is 100 cm2. What open-circuit voltage will it produce when operated as a microphone with an rms diaphragm velocity of 10 cm/s?
Solution. From Fig. 3.35 we see that, always,
The power dissipated W gives us the rms volume velocity of the diaphragm U rms: