Orban OPTIMOD 6300 Operating Manual page 154

3-12
OPERATION
loudness controller from causing too much dynamic bass boost, you can use the
L C
OUDNESS ONTROLLER
tween the gain of the band below 200 Hz and the band above 200Hz. For example,
when this control is set to 3
the gain reduction below 200 Hz will be 7 dB. However, if the loudness controller's
gain reduction is 2 dB, the gain reduction below 200 Hz will be 0 dB because the dif-
ference is now less than 3 dB.
The loudness controller is triggered mainly by program material that has a lot of en-
ergy between 1 and 7 kHz, which is the ear's most sensitive range. If you are using
the two-band structure and you find that the loudness controller is producing audi-
ble artifacts because the program forces it to do a great deal of gain reduction, we
suggest that you use the five-band structure instead. This will automatically re-
equalize such program material and will de-ess extremely sibilant program material
before the loudness controller receives it.
The loudness controller's attack and release times are tuned to match the loudness
integration times of the ear and are program-adaptive. Only the attack time is user-
adjustable.
If you feel that the Loudness Controller is not controlling the loudness of commer-
cials or other subjectively loud program material sufficiently well, you may wish to
set the threshold lower, forcing the Loudness Controller to do more work. Con-
versely, if the loudness controller is doing more gain reduction that you would like,
you can set the L
OUDNESS
The Loudness Controller produces both fast and slow loudness control; the fast con-
trol rides on top of the slow control. You can easily see this dual-speed operation on
the L GR meter. The L
OUDNESS
control the Loudness Controller produces. As the control is turned down toward 0%,
it allows longer and longer loudness peaks to pass through.
The 6300's ITU-R BS.1770-2 loudness level meter monitors the output of
the peak limiter and hence takes into account both the fast and slow
components of the CBS loudness controller's gain reduction. The Loud-
ness Level meter on the 6300's front panel indicates BS.1770-2 loudness.
This is the meter specified in ATSC Recommendation A/85 and EBU R 128
and is the meter used to verify that the 6300 is controlling loudness in
compliance with the CALM Act.
The 6300's CBS Loudness meter is only visible from PC Remote software,
which displays the BS.1770-2 meter beside the CBS meter. Because of the
system topology, the 6300's CBS loudness level meter always reads as it
would if the L
dicate the effect of lower settings. As long as the control is set to 50% or
higher, this limitation should not have any significant effect on the CBS
loudness level meter's accuracy.
The Loudness Controller may reduce the dramatic effect of certain sounds in enter-
tainment programming, like gunshots, explosions, or screeching tires. Operators may
therefore want to turn the Loudness Controller on during commercial breaks and
off during normal programming. All sound-for-picture presets have the Loudness
Controller on. The easiest way to handle this situation is to start with your preferred
B C
ASS OUPLE control to limit the maximum difference be-
and the loudness controller's gain reduction is 10 dB,
DB
T
HRESHOLD control higher.
A
OUDNESS TTACK
A
control were set to 100% and does not in-
OUDNESS TTACK
ORBAN MODEL 6300
control determines how much fast