Orban OPTIMOD 6300 Operating Manual page 46

1-22
INTRODUCTION
subjective loudness.
 Input levels are displayed using a VU-type scale 0 to –40dB), but the metering
indicates absolute instantaneous peak (much faster than a standard PPM or VU
meter). The maximum digital word at the input corresponds to the 0 dB point on
the 6300's input meter.

The output meter indicates the values of the digital samples at the output of the
6300's audio processing, not at its digital outputs. For example, if the DO1 100%
control is set to –3 dBFS and the meter indicates 0 dB, the peak level at the
6300's digital output #1 is –3 dBFS.
0 dB on the meter also corresponds to the threshold of limiting of the 6300's
look-ahead peak limiters, which prevent the processed audio's level from increas-
ing beyond 0 dB.
If the output's sample rate is set to a rate other than 48 kHz and or
passed through a D/A converter, the peak level of the output may in-
crease by as much as 0.5 dB because the 6300's peak limiter is oversam-
pled at 192 kHz and not at infinite frequency . (See page 1-16).

The subjective loudness meter, labeled L
displays long-term gated loudness measured by the ITU-R BS.1770-2
with a ten-second integration time where all samples in the previous ten seconds
are weighted equally. In addition to BS.1770-2, 6300 PC Remote indicates short-
term loudness measured using the CBS Technology Center algorithm developed
by Jones and Torick
 If the 6300's D
The meter is scaled so that in Dolby Digital transmission channels, the loud-
ness level at the consumer's receiver is correct when the 6300's processing is
adjusted to make dialog peak at "0 dB" on the 6300's Loudness Level meter
and the Dialnorm value (which you must enter manually) in the active 6300
Setup is the same as the Dialnorm value being transmitted to the consumer's
receiver.
 If the 6300's Dialnorm feature is not active (i.e., when the D
R O
EFERENCE UT
You can still arbitrarily set the meter's sensitivity by adjusting the 6300's
D
control, although this control will no longer affect the loudness of
IALNORM
the 6300's output. This allows you to compare the loudness of various 6300
presets, whether Factory or User.
1
Recommendation ITU-R BS.1770-2 (03/2011): "Algorithms to measure audio pro-
gramme loudness and true-peak audio level"
2
Bronwyn L. Jones and Emil L. Torick, "A New Loudness Indicator for Use in Broad-
casting," J. SMPTE September 1981, pp. 772-777.
2
.
R O
IALNORM EFERENCE
control = OFF):
L
on the 6300's front panel,
OUDNESS EVEL
UT control is assigned to DO1 or DO2:
ORBAN MODEL 6300
1
standard
IALNORM