A 24 Ω loudspeaker and an 8 Ω loudspeaker are connected in parallel across the terminals of an amplifier. Assuming the speakers behave as resistors, how do you calculate the equivalent resistance of the two speakers?

1 Answer
Feb 2, 2016

Add the value of the resistors in parallel using the formula:
#R = 1/(1/R_1 + 1/R_2)#
#R = 1/(1/24 + 1/8) = 6" ohms"#


What is interesting about this question is that the person who asked it seems to know a lot about the answer already. The impedance of an audio speaker varies depending on the frequency of the input signal.

The questioner also understands that speakers are built with particular input impedance characteristics. 8 ohms is the most common. But 24 ohm speakers are used in many applications.