Dolby Laboratories 737 - Manual (Page 32)

Model 737 Soundtrack Loudness Meter - Leq(m) Background
A-6
Figure A-3 CCIR-weighting (Leq(m)) shows influence of 2–6 kHz region.
A.4 Analysis of the Data
Figure A-4 shows the relationship between un-weighted (Leq) and CCIR-weighted
(Leq(m)) samples. The hierarchy on the right of the figure (un-weighted) differs from
that on the left (weighted). The slope of the connecting lines denotes the amount of bass
content in the program. Lines with higher slopes indicate larger amounts of bass, while
horizontal lines (0 slope), or lines with negative slope indicate less bass content. Of the
samples shown, notice that Indiana Jones and the Temple of Doom is raised in the
hierarchy due to the lack of bass in the five-minute sample. This matches the apparent
loudness of the sample, one of the loudest Dolby A-type films.
S m irn off
d ea th
w a tch
d um m ie s
L ev is
S an y o
R A F
w ater
7 5
8 0
8 5
Leq C C IR -w eighted
Leq
m
Leq A -w eighted
Leq
a
5.6 dB offset
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