Orban OPTIMOD-FM 8700, Руководство по эксплуатации

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OPTIMOD-FM DIGITAL OPERATION
3-17
Input/Output Delay
The sophisticated look-ahead algorithms in the 8700i have one significant cost—the
input/output time delay is longer than that of an analog processor and can cause
problems if an off-air pickup is used to feed talent headphones.
To make intelligent decisions about how to process, the 8700i needs to look ahead
at the next part of the program waveform. (Slowly changing bass waveforms require
particularly long look-ahead delays.) As digital on-air processing advances further
and further from its analog roots, this is the inevitable price of progress.
The amount of delay depends on several things. Because of their unprecedentedly
sophisticated processing, “MX” presets introduce delays of approximately 265 ms,
which makes real-time monitoring through headphones impossible for talent. The
8700i offers a low-delay headphone monitoring output to solve this problem, which
also occurs in HD Radio installation where the diversity delay is typically 8-10 sec-
onds.
If a non-MX preset is active, the delay is usually low enough to allow talent to moni-
tor live through headphone although a learning period may be required.
For a thorough discussion of delay issues and solutions, see Monitoring on Loud-
speakers and Headphones on page 1-26.
Customizing the 8700i’s Sound
The subjective setup controls on the 8700i give you the flexibility to customize your
station’s sound. Nevertheless, as with any audio processing system, proper adjust-
ment of these controls requires that you choose the desired audio texture for your
station while managing the trade-offs between loudness, density, and audible dis-
tortion. The following pages provide the information you need to adjust the 8700i
controls to suit your format, taste, and competitive situation.
When you start with one of our Factory Presets, there are three levels of subjective
adjustment available to you to let you customize the Factory Preset to your require-
ments: Basic Modify, Intermediate Modify, and Advanced Modify.
Basic Modify
Basic Modify allows you to control three important elements of 8700i processing:
the stereo enhancer, the equalizer, and the dynamics section (multiband compres-
sion, limiting, and clipping). At this level, there is only one control for the dynamics
section:
L
ESS
-M
ORE
, which changes several different subjective setup control settings
simultaneously according to a table that we have created in the 8700i’s permanent
ROM (Read-Only Memory). In this table are sets of subjective setup control settings
that provide, in our opinion, the most favorable trade-off between loudness, densi-
ty, and audible distortion for a given amount of dynamics processing. We believe
that most 8700i users will never need to go beyond the Basic level of control. The
combinations of subjective setup control settings produced by this control have been