User`s manual

5. Menu and toolbar
Barco – iStudio – R5976569 – user's manual – revision 09 – March-2007
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Furthermore two Phase bars, each showing the phase between two adjacent audio channels, can be displayed.
Therefore the respective phase bar checkbox must be selected and the two audio channels must be chosen from
the list. The phase bars are then displayed on top of the respective object. The phase bar is displayed as a gray
bar with a scale from -1 to +1. Positive values are displayed as a green block ranging from 0 to the value. Nega-
tive values are displayed as violet block ranging from 0 to the value. Values in the range of +1 indicate that both
sources are in phase and of acceptable level. Values in the range of -1 indicate that the signals are out of phase
but of acceptable level. Values in the range of 0 indicate either that there are completely different signals or that
both signals are not of acceptable level or that the signals have a phase difference of about 90°.
The audio reference level can be adapted to the level of the input signal by means of the two audio reference
sliders on the bottom of the dialog. Depending on the audio type and scale type the setting of the one or the
other or both sliders have to be used. Please see the table below:
Signal A/D Reference 0 dBu Reference
digital audio on digital scale no effect no effect
digital audio on analog scale shift the reference level no effect
analog audio on digital scale no effect shift the reference level
analog audio on analog scale shift the reference level shift the reference level
The range for A/D Reference and 0 dBu Reference depend on the type of the selected audio sources:
type of audio source A/D Reference 0 dBu Reference
embedded / external -1 .. -24 dBfs -20 .. +20 dB
NGM-164 -10 .. -30 dBfs -12 .. +12 dB
The Update button on the bottom of the dialog assigns the audio channels to the sources in
the indicated way. The Reset button restores the default values, but it does not update!
An explanation of definition and ballistics of the audio bars and phase bars is given below:
The audio bars are displayed according to the respective international standard:
BBC PPM, DIN, Nordic Peak Program Meter IEC 60268-10 International standard
VU, Extended VU Volume Indicator meter IEC 60268-17 International Standard
AES/EBU Digital audio peak level meter IEC 60268-18 International standard
Ballistics is integration time and decay time of the audio level meters. It is built in accordance to the above men-
tioned international standards with the following meaning:
• Integration time is the time between the moment when the indication passes the specified lower point of
the scale and the moment when the pointer reaches the reference indication.
• Decay time is the time between the removal of a steady-state input signal (corresponding to reference
indication) and the moment when the indication passes a specified lower point of the scale.
Ballistics of the audio phase meters is built as follows:
• Integration time is the time between the moment when the indication passes the 0 point of the scale and
the moment when the pointer reaches +1 (or –1).
• Decay time is the time between the removal of a steady-state input signal (corresponding to +1 or –1 indi-
cation) and the moment when the indication reaches the 0 indication.