3Com CP-1 Two-Way Radio User Manual

Page 28
Program Parameters cont'd
The Programs:
Auto Azimuth/
The AUTO AZIMUTH/BAL parameter should be set to ON for films, OFF
for music. When it is on, special digital circuits continually monitor the
dialog and adjust both the relative level and time offset of the two channels
to keep the dialog properly centered. This automatic feature is why the CP-
1 does not have or need a front-panel input balance control for Dolby
Surround decoding.
BASS BLEND takes the low bass from the center, where it is in many film
and music mixes, and distributes it instead to the left and right front-
channel speakers. Its initial value is 0 in the Stereo Logic program and 6 in
Pro Logic. This is valuable because in many video installations the center
speaker is smaller than the two main stereo speakers and is, therefore, less
capable of handling the lowest frequencies.
Bass Blend
The essence of the Dolby PRO LOGIC circuit is that dialog, music and sound
effects are dynamically directed to the output channels, a process called
steering. The FRONT EFFECT and REAR EFFECT parameters in Stereo
Logic allow you to adjust the amount of this steering. Both are preset for
their maximum values in PRO LOGIC. In STEREO LOGIC, FRONT
EFFECT has a default value of 8, which is equivalent to 6 dB of steering; at
this level, central (monaural) sources are reduced in level by 6 dB in the main
stereo speakers. With FRONT and REAR EFFECT both set to 0, STEREO
LOGIC becomes the equivalent of a simple non-steered Dolby Surround
decoder. If you have no rear speakers, REAR EFFECT should be set to 0. The
CP-1 will set this parameter automatically when you specify a speaker
configuration with no rear channels. (See page 13.)
Front Effect/
Rear Effect
Dolby Surround decoding specifications call for a special form of Dolby B-
type noise reduction. Because STEREO LOGIC is also meant for music, the
rear-channel sound has more flexibility, including REAR NOISE CHIP, a
parameter that allows you to turn this Dolby NR circuit off.
The CALIBRATE mode in Stereo Logic and Pro Logic is for setting up and
checking the levels of the channels in multi-speaker systems. Its use is
covered in the section on Balancing Additional Channels on page 10.
The procedures for naming a new version of the program (SET PROGRAM
NAME) and storing it in one of the User registers (MEMORIZE PROGRAM)
are described on page 29.
Set Program Name/
Memorize Program
Rear Noise Chip