dBFS

DB FS ( wrong, but often used: dBFS ), Eng. Short for " decibels full scale " is the logarithmic unit with absolute, often linear scale in a digital audio engineering system.

An analog full-scale level value produced the maximum linear positive or negative value in the digital word length of the A / D converter. The dB FS- values ​​, however, know for a single sample only negative values ​​and 0 as the full scale. For display on the dB FS- scale of the digitized voltage value is converted. ( In principle, any sizes are represented by decibels and thus dB FS. )

Peak value ( peak value)

0 dBFS represents the highest possible level value represents (eg 32767 / -32768 for 16- bit). A higher -level value than 0 dBFS for a single sample is not possible in the digital domain. AD / A converter can but in special cases, higher level ( in the analog domain ) generate, this may result from particular selected digital samples of the waveform and the transducer characteristics.

RMS

The RMS value is a possible variant of averaging a number or series of measurements. For audio measurements, this algorithm is well suited to the mechanical original from the analog world is the moving iron.

FS Square Wave ( full-scale square wave ): The rms value of the maximum possible square wave is denoted here by 0 dBFS. It follows that a sine wave, reached their highest single sample in the top 0 dBFS is effectively displayed with -3 dBFS RMS.

FS Sine Wave (Full - Scale Sine Wave): The rms value of the maximum possible sine wave is increased by 3 dB to 0 dBFS. It follows that a square wave, reached their highest single sample in the top 0 dBFS is effectively displayed with 3 dBFS RMS.

This scaling 3 dB is made ​​so that a full level sine wave ( test tone) is displayed on the VU to 0 dBFS. The FS- square-wave representation (-3 dBFS ) sine of a would lead to the false assumption that the sine tone have not yet reached the full scale. In order to delineate the peak - viewing (FS Square Wave), the term " dBFS RMS" is sometimes used. This is also called " intrinsic level".