Dante Inovonics 541, Installation & User Manual, Page: 34 / 56

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Integrated
Loudness
History
This screen plots the loudness level of the FM broadcast, ad-
hering to the ITU-R BS.1770 Standard discussed on Page 24.
These readings are integrated (long-term) “LU” loudness meas-
urements.
Per the previous dis-
cussion, LU numbers
don’t equate well with
total carrier modula-
tion peak readings, as
LU measurements are
both frequency- and
time-weighted.
The LU Y-axis scale at
the right of the screen
actually auto-ranges
to always give the best
level resolution over
the displayed time pe-
riod. As you change
the
Time Span:
to cover a longer sampling period, vertical scal-
ing will change to accommodate the level range for that partic-
ular timeframe.
MPX Power
Similar in function to
the Loudness History
utility just described,
MPX Power
instead
reflects the ITU-R
BS.412-9 Standard for
total r.m.s. power of
the FM-multiplex sig-
nal. You may wish to
refer back to the dis-
cussion on Page 24 for
an understanding of
just what this implies.
The readout here is in
dBr, and as mentioned
in the previous dis-
cussion, European broadcasters under ITU jurisdiction may be
limited in total MPX power to something in the 0dBr range,
perhaps as scandalously high as +3dBr. Note that in our ex-
ample here, a typical major-market US broadcaster is running
MPX power some 15dB above his old-world counterparts…
that’s more than a 30-fold MPX power increase!