Commercials Too Loud In Sound For Picture Applications; Commercials Too Quiet; Loudness Incorrect Compared To Other Dolby Digital Transmissions - Orban OPTIMOD 6300 Operating Manual

5-6
TROUBLESHOOTING

Commercials too loud in sound for picture applications

Commercials too quiet

Loudness incorrect compared to other Dolby Digital Transmissions


Make sure that the Loudness Controller is activated on the preset that you are
using—the L
OUDNESS
3-51) and is normally set to –10 dB.

If the Loudness Controller is active but based on its gain reduction meter, you do
not believe it is working hard enough, set its threshold lower using the L
C T
ONTROLLER HRESH
Note that the Loudness Controller controls subjective loudness to an ab-
solute threshold and does not understand the context of the program.
Therefore, if a commercial follows a piece of very quiet program mate-
rial, the commercial may still seem loud even though the Loudness Con-
troller is working properly.
See Loudness Control on page 3-11.

This can be a side effect of your Optimod's BS.1770 safety limiter and is caused
by the tendency of the BS.1770 algorithm to over-indicate the loudness of mate-
rial with an unusually low peak-to-average ratio. In this case, the BS.1770 safety
limiter is making the BS.1770 meter read "correctly" even if the material sounds
quieter to your ear. To reduce this effect, set the BS.1770 L
trol to +2 LK or above See BS.1770 Safety Limiter on page 3-13 for a more de-
tailed discussion.

Review Setting Preset Loudness Correctly in Dolby Digital Transmission on page
3-17.

Be sure that the 6300 output (DO1 or DO2) driving your Dolby Digital encoder is
set as the D
IALNORM

Be sure that the active D
setting you are transmitting to consumers. Use a device like the Dolby LM100
Loudness Meter to read out the Dialnorm you are transmitting to your audience
(or simply check the Dialnorm setting of your Dolby Digital encoder).

Make sure that the AI R
ing the analog or digital input) is set up correctly (step 5 on page 2-21 or step 7
on page 2-23).
Note that only "TV" presets are designed to produce calibrated loudness
when used with the 6300's Dialnorm support. Any radio-style preset can
be edited to activate the Loudness Controller.

If the CBS loudness controller is on, be sure that the L
is set to 0 dB.
This matches the loudness controller's threshold to the 6300's active
D
IALNORM
C T
ONTROLLER HRESH
control.
R O
EFERENCE UTPUT (see step 12.B)a) on page 2-30).
setting in the 6300 is the same as the D
IALNORM
or DI R
control (depending on whether you are us-
EF EF
value.
ORBAN MODEL 6300
control must not be set O
IMIT
T
OUDNESS HRESHOLD
(see page
FF
OUDNESS
T
HRESHOLD con-
IALNORM
control