[Arny Krueger]

"Randy Yates" wrote in message


What units would a typical professional digital audio
system use to measure RMS values of digital signals?

The well known DAW software packages Cool Edit Pro and Adobe Audition both
have a measurement tool that produces both peak, average, and RMS values.
The measurement interval is the range of the wave that is selected and
highlighted on the screen. They provide their measurements in dB FS.

Signal values in DAW programs are typically dimensionless because they are
dependent on the gain of the ADC that was used to digitize them, perchance
they once existed as analog voltages. The gain of ADCs is not standardized
and is often not even carefully specified. Pro audio ADCs often have
continuously-variable analog or digital attenuators on their inputs. If you
stabilize the settings of the input attenuators, then Pro Audio ADCs can be
calibrated. I use an analog meter and sine waves for the purpose.

The RMS and peak values of a dimensionless quantity are themselves both
dimensionless.