NTi Audio Digilyzer DL1 - Manual (Page 43)

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Level RMS
The analog Level RMS function measures the RMS level of the digital
input signal. Since the Digilyzer has no information about the reference
voltage, such as the
• value to digitize the analog signal
• value to convert the digital signal into the analog domain
The RMS values are displayed as relative numbers compared to a
sine wave signal with 0 dBF (peak value).
result and unit: The RMS level of the individual selected channel
can be displayed in three different units:
• dBr (decibel relative)
• % (percent of full scale)
• x1 (number)
In case the measured RMS value is smaller than -100 dBr, the
Digilyzer displays “<-100 dBr“.
Filter: The audio signal decoded from the digital audio stream can
alternativelly be filtered with the following filters prior to the RMS
or THD+N calculations:
• HP400, highpass 400 has a good rejection in the area of main
frequencies – so hum problems may be easily examined and
localized. The HP400 is also used to measure quantization
noise.
• 22-22k, bandpass 22-22k is used to define the commonly used
measurement bandwidth from 22Hz to 22kHz.
Fig 5-42, Level RMS
Result
and unit
Display mode Filter
Audio frequency
Measurement Functions