Manual

LM2 (optional)
Loudness Pilot English Manual (2014-10-07) 105
Prog. Loudn. setting
Program Loudness returns one loudness num-
ber for an entire program, film or music track. Its
unit is LUFS. Some vendors and countries use
the unit “LKFS” or “LUFS”, but all three desig-
nate the same: An absolute measure of loudness
in the digital domain, where the region around
“0” is overly loud and not relevant for measur-
ing anything but test signals. Expect readings of
broadcast programs in the range between -28
and -20LUFS.
Program Loudness is used as a production
guideline, for transparent normalizing of pro-
grams and commercials, and to set loudness
metadata in delivery if so required.
For delivery or transmission of AC3 format, the
metadata parameter “dialnorm” should reflect
Program Loudness.
The easiest way to handle multiple broadcast
platforms is to normalize programs at the sta-
tion to a certain value, thereby being able to take
advantage of the normalization benefits across
platforms, at the same time enabling static meta-
data.
Loudness measurements in LM2 are all rooted in
ITU-R BS.1770. However, subtle differences exist
between different regions of the world. Therefore
LM2 also includes the “Loudness Standard” pa-
rameter. Be sure to set this parameter correctly
for compliance in your region.
The Program Loudness target is more or less the
same for broadcasters around the world, espe-
cially when taking the measurement differences
into account. Target numbers range between -24
and -22LUFS.
Like with Loudness Range and Loudness Max,
the meter should be reset before measuring Pro-
gram Loudness.
Sliding Loudn. setting
Unlike Loudness Range, Program Loudness and
Loudness Max, Sliding Loudness is a continu-
ously updated measure that doesn’t need to be
reset. This type of descriptor is especially use-
ful when “mixing by numbers” – i.e. when there
is no access to the extremely informative radar
display.
When mixing by numbers, having Program Loud-
ness as one descriptor and Sliding Loudness
as the other displays simultaneous information
about the full program side by side with the most
recent loudness history.
Because the Sliding Loudness measurement
is completely ungated, it may also be used to
spot-check sections of a program complying
to “raw” ITU-R BS.1770 and the first revision of
ATSC A/85.
LM2 makes use of optimized statistics process-
ing in order to display a sliding loudness value (a
prognosis) as quickly as possible after a reset.
Loudness Max setting
Loudness Max displays the maximum loudness
registered since the meter was last reset. Loud-
ness Max is an especially useful parameter when
checking and normalizing short duration pro-
grams such as promos and commercials.
BCAP rules from the UK is an example of us-
ing Loudness Max as an efficient instrument to
reduce listener complaints regarding loud com-
mercials. While Program Loudness is adequate
to normalize a consistent mix, Loudness Max
may be used as a second line of transparent de-
fense against overly short and loud event.