Question

When the volume control on a stereo system is increased, the voltage across a loudspeaker changes from V1 to V2, and the decibel increase in gain is given by
db = 20 log [V2/V1]

Find the decibel increase if the voltage changes from 3 volts to 4.5 volts.

Answer 1

V1 = 3 , V2 = 4.5

V2 / V1 = 4.5 / 1.5 = 3 ∙ 1.5 / 3 = 1.5

dB = 20 ∙ log ( 1.5 )