Definition of DBFS
dBFS or dB FS (decibels relative to full scale) is a unit of measurement for amplitude levels in digital systems, such as pulse-code modulation (PCM), which have a defined maximum peak level. The unit is similar to the units dBov and decibels relative to overload (dBO).
The level of 0 dBFS is assigned to the maximum possible digital level. For example, a signal that reaches 50% of the maximum level has a level of −6 dBFS, which is 6 dB below full scale. Conventions differ for root mean square (RMS) measurements, but all peak measurements smaller than the maximum are negative levels.
A digital signal that does not contain any samples at 0 dBFS can still clip when converted to analog form due to the signal reconstruction process interpolating between samples. This can be prevented by careful digital-to-analog converter circuit design. Measurements of the true inter-sample peak levels are notated as dBTP or dB TP (decibels true peak).
Terms mentioned above
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Questions people ask
Real questions from the Stack Exchange community – follow a link to read the discussion.
- What is the difference between dBFS and dBu? · Sound Design SE
- How to input noise values in dBFS for ffmpeg silence detect · Video Production SE
- How do I calculate the adjustment to a target dbFS? What's the formula? · Video Production SE
Frequently asked questions
What is DBFS?
dBFS or dB FS (decibels relative to full scale) is a unit of measurement for amplitude levels in digital systems, such as pulse-code modulation (PCM), which have a defined maximum peak level.
Sources & credits
- Wikipedia: DBFS – CC BY-SA 4.0
- Image by H2g2bob – CC BY-SA 4.0