Table of Contents
Advertisement
3-6
OPERATION
Sound-for-Picture Applications: Controlling Dynamic Range
About the 6300's Signal Processing Features
Signal Flow
mitted to audibly degrade the sound of the original program material, the signal is
irrevocably contaminated and the original quality can never be recovered.
The most crucial commandment in sound for picture is this: dialog must always be
intelligible. Sound for picture is usually heard under less-than-ideal conditions and
its dynamic range must be controlled accordingly. Apartment-dwellers must set their
volume controls to avoid disturbing neighbors or even other members of the family.
At the quiet side, intelligibility of dialog is often impacted by environmental noise
such as children playing or a dishwasher going in the kitchen. When one considers
that the hearing acuity of a significant portion of the audience is somewhat im-
paired compared to that of a healthy 20-year-old, one concludes that the dynamic
range of dialog must not exceed 15dB if it is to be intelligible to 99% of viewers un-
der common domestic viewing conditions. Feature-film dynamic range is inappropri-
ate for home viewing (except in dedicated home theaters) and the dynamic range of
a significant portion of video source material must be compressed to best serve the
audience. The challenge (which Optimod 6300 effectively meets) is to compress dy-
namic range unobtrusively.
OPTIMOD 6300 can be adjusted so that the output sounds as close as possible to the
input at all times (using the 2-band Protection Limiter preset), or so that it sounds
open but more uniform in frequency balance than the input (using the 2-band struc-
ture or running the 5-band Structure with slow release time), or so that it sounds
dense, quite squashed, and very loud (using the 5-band Structure with faster release
times).
The dense, loud setup is almost always inappropriate for sound for picture unless
the station has unusual programming and goals. Most stations will want to use sim-
ple protection processing when broadcasting material that has been carefully pro-
duced by people cognizant of the dynamic range limitations of sound for picture.
For most other program material, the 2-band or Slow 5-band structures are appro-
priate.
The subjective setup controls on the 6300 give you the flexibility to adapt the proc-
essing to individual program segments. In most cases, your goal should be to choose
the type of processing that best optimizes dynamic range while controlling the
loudness of the loudest sounds so that they are not irritating and are consistent with
the loudness of other stations or sources.
The signal flows through the 6300 through the following blocks (see page 6-41):
ORBAN MODEL 6300
Advertisement
Table of Contents
Troubleshooting
