What is dBu and dBFS?


What is dBu and dBFS?

dBFS, or “decibels relative to full scale,” is used to measure amplitude levels in digital systems that have a maximum peak level (the point at which the A/D converter will clip). When measuring in dBFS, 0 dBFS cannot be exceeded. 0 dBFS can equal +10 to +24 dBu, depending on the device’s maximum peak level.

What voltage does a level of +4 dBu correspond to?

1.23 volts
A rating of +4 dBu in equipment specifications implies a reference or nominal voltage of 1.23 volts. Keep in mind that voltage does not relate to decibels linearly. It is a logarithmic function.

How do you convert dBu to dBV?

Essential Formulas

  1. dBV = dBu – 2.21.
  2. Volts = 10(dBu / 20) x 0.775.
  3. dBu = dBV + 2.21.
  4. Volts = 10(dBV/20)
  5. dBu = 20 log (Volts/0.775)
  6. dBV = 20 log (Volts)

Is dB the same as dBu?

dBu and dBV are decibel units specifically for measuring voltage. Unlike the dB, they are actually units because they can be converted to an actual voltage value. dBu is dB relative to 0.775 volts; such that 0dBu = 0.775 volts. dBV is dB relative to 1.0 volt; such that 0dBV = 1.0 volt.

What is a +4 line level?

2. Professional Line Level (+4dBu) Professional audio equipment adheres to the professional line-level standard that is technically +4dBu (Sorry!), commonly referred to as just +4.

How is dBfs calculated?

Since the RMS of the full-scale sine wave is 1/sqrt(2) , multiplying rms(signal) by sqrt(2) ensures that the formula evaluates to 0 for the full scale sine wave: 20*log10(rms(signal) * sqrt(2)) = 20*log10((1/sqrt(2)) * sqrt(2)) = 20*log10(1) = 0 .)

How do you calculate dBV?

The formula for calculations is the same as for dBu: dBV = 20log (V2/V1). The dBV rating is most commonly found in consumer equipment that uses nominal operating levels of -10 dBV. It is simply a standard that was adopted many years ago.

How do you convert to dBu?

The conversion from voltage V (volt) to level (dBu) is L = 20 × log (V/0.775).

What does dBFS mean?

The term dB FS (or dBFS) means decibels relative to full scale. It is used for amplitude levels in digital systems with a maximum available peak level, e.g., PCM encoding, where 0 dB FS is assigned to the maximum level.