Juice Sound Ltd








Gain shown in Ratio (Approx)








Db = Gain (or multiplier)



20 = 100



15 = 31.5



10 = 10



5 = 3.16



4 = 2.5



3 = 1.995



2 = 1.585



1 = 1.259



0 = 1



-1 = 0.794



-2 = 0.631



-3 = 0.501



-4 = 0.398



-5 = 0.316



-10 = 0.100



-15 = 0.0316



-20 = 0.0100








The Decibel is a measurement of reference between two levels and not a



definite reference point in itself i.e. 0db has no figure until referred to another



relative point. Therefore a voltage difference can be displayed in Db's



for example the voltage difference between 1v to 0.5v could be displayed



as -50% or -0.5 of a volt or in Db's -3db. The same reference can be used for



the difference between 3v and 1.5v. The real usefulness becomes obvious when



you are talking in large differences because Db's are logarithmic and therefore



fairly small figures in Db's can explain vast differences between reference points



such as the huge gain from microphone level to line level within a mixer.








Originally designed by the Bell Telephone Laboratories, the Bel and (decibel =



One tenth of a Bel) was used for measuring levels in telephone systems



see https://en.wikipedia.org/wiki/Bell_Labs on the amazing company



or see https://en.wikipedia.org/wiki/Decibel for information on the Decibel