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Peak Level
Range: -1 to -10 dBFS (1 dB steps).
The Peak level is a user defined reference point.
The peak level is dependent on the setting of ‘Peak Mode’;
True Peak or Digital (Sample Peak).
When the signal passes above the peak level, the Peak level readout will turn Red.
Gate Level (-a)
Range: -8 to -20 dB (1 dB steps).
It is often the high level parts of a program which are often of most interest for assessing compliance with
broadcast criteria. To prevent an extended length of low level program content reducing the averaged loudness
value to a degree that affects the measured value, the meter has an optional gating function. Once the signal
drops below the gate threshold, the meter will continue to hold, display and use for averaging purposes, the
previous value that was above the threshold. Setting it to -20 causes the gate to remain open and the unit
displays the actual loudness for the vast majority of the time.
Gate Level (-b)
Range: Floating or Absolute.
The gate level can be an absolute value or a floating one. Absolute values offer a degree of simplicity but at the
risk of a high setting causing gating of quieter sections which might sometime comprise a significant part of
material such as a feature film soundtrack. Adopting a low absolute value can cause background noise that is at
a relatively high level (for example a documentary by a waterfall) not to be gated out, even though it is not a
significant contributor to the perceived loudness. Making the gate level relative may then offer results that more
closely reflect perceived program loudness.
Peak Mode
Range: Digital or True Peak.
Selecting Digital will base the reading on individual sample values.
True Peak uses oversampling to create the maximum intersample peak possible taken from the maximum value
of the interpolated waveshape.
Reference
This is the frequency chosen for the calibration alignment and is either 400 or 1000 Hz.
Capture
The Loudness capture functionality may be changed between two different modes; Start-Pause and Auto-Start.
Loudness measurement or Capture is essentially always done over a timespan - hence, it is necessary to define
when the Loudness capture starts and stops.
As explained in the Loudness & Terminology section, several different Loudness measures are relevant i.e.
Momentary Loudness, Short-term Loudness, Integrated Loudness and Loudness Range – all time dependent.
The Start-Pause Mode
