What is the meaning/definition of 0 dBV?

Answer 1

dB is decibels. It's the log of the ratio of two things.
When you divide something with a unit (feet, kilograms) by another value with that unit, the result is just a number, without a unit. Examples: 3/5 or 5/8 or -10 or +3.

So the V tells you the reference. V typically stands for Volts- 1 Volt in this case.

1Volt/1Volt = 1. The log of this is 0, or 0 dBV

Answer 2

A dBV is a way to express the amplitude or power of a changing voltage present on a wire. Imagine that the voltage measured over time looks like a sine wave, and the peak of the sine wave is at +/- 1.41 volts then the "power" of the voltage is 0 dBV. This is also the same as a RMS voltage of 1 V. RMS stands for Root Mean Square and is another way of representing an average value for a varying signal.

So 0 dBV is the same as 1 Vrms is the same as 1.41 peak (2.82 volts peak-to-peak).

A rule of thumb to follow for dBV is that an increase of 6 in the value is approximately a doubling of the RMS voltage (but not exactly). So:

0 dBV = 1 Vrms
6 dBV ~ 2 Vrms
12 dBV ~ 4 Vrms
18 dBV ~ 8 Vrms

Hope that helps!

Answer 3

Dbv Definition