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