Comparing The Meters - Orban OPTIMOD-PC 1101 Operating Manual

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OPERATION

Comparing the Meters

veloped after 15 years of psychoacoustic research at CBS Laboratories, the CBS loud-
ness controller accurately estimates the amount of perceived loudness in a given
piece of program material. If the loudness exceeds a preset threshold, the controller
automatically reduces it to that threshold. The CBS algorithm has proven its effec-
tiveness by processing millions of hours of on-air programming and greatly reducing
viewer complaints caused by loud commercials.
Since first licensing the CBS algorithm and using it in its Optimod-TV 8182 in the ear-
ly 1980s, Orban has continually refined and developed this technology. In the last
30+ years, audio processors from Orban and CRL using the CBS loudness controller
have processed millions of hours of on-air television programming — an unsur-
passed track record that no other subjective loudness controller technology can
claim.
Because the ATSC recommends the BS.1770 algorithm, many broadcast and cable
engineers facing the problem of controlling broadcast loudness have wondered how
the CBS and BS.1770 technologies compare. An earlier version of this Orban white
paper compared the CBS and BS.1770-1 (non-gated) meter. The paper you are now
reading was revised in March 2012 to incorporate results from tests using the
BS.1770-2 algorithm and EBU – TECH 3342 "Loudness Range" algorithm. The new
measurements were performed using Version 2 of the Orban Loudness Meter
revision compares the CBS and BS.1770-2 meters because we expect that the ATSC
will eventually update A/85 to specify BS.1770-2, which will more closely harmonize
A/85 with its European counterpart, EBU R 128.
A/85 and R 128 differ significantly in their philosophy and recommendations. Proba-
bly most important difference is that A/85 asserts that the loudness of a so-called
"anchor element" (which is typically dialog except in programs emphasizing music,
like live concert recordings) is most important, while R 128 asserts that the inte-
grated loudness of the entire program is most important
loudness should be normalized based on an integrated BS.1770-2 measurement. The
philosophy behind A/85 is similar to that of Dolby Laboratories, which for many
years has asserted that dialog anchors most film and television programs and that
listeners set their volume controls to make dialog comfortably intelligible
agree more with A/85 than with R 128).
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This software is available for free download at http://orban.com/meter/.
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EBU – TECH 3343, "Practical guidelines for Production and Implementation in ac-
cordance with EBU R 128," version 1 (February 2011), p. 29
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Riedmiller, J., Lyman, S., Robinson, C., "Intelligent program loudness measurement
and control: what satisfies listeners?" AES Convention Paper 5900, 115
(October 2003)
ORBAN MODEL 1101
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