Dolby Laboratories CP65 - Manual (Page 55)

B-Chain Alignment Procedures
Action Indication Step
No.
5-32
e. Surround Equalization Alignment (Cat. No. 441)
1
2
OFF
RIGHT
3
85 dBC
STEREO SURROUND
88 dBC
MONO SURROUND
Dolby
gain mono
non-sync
gain
points
test
mono eq
Ls
R
C
L
Ls
R
C
L
gnd
Ls
R
C
L
R
L
signal present
Cat. No.
242
04 Dolby Stereo
A-type
O FF 80 7 0 6 0 50 4 0 30
Re
S
B-Chain Alignment Procedures
Notes
5-33
e. Surround Equalization Alignment (Cat. No. 441)
If your CP65 does not contain the Cat. No. 441 Surround Equalizer and Subwoofer Card,
skip this paragraph and go directly to page 5-42, Adjustment of Surround Delay. The
CP65 will function without the Cat. No. 441 card, but the surround frequency response
cannot be equalized.
The surround equalizer on the Cat. No. 441 card consists of:
• A parametric mid-band section with variable cut, bandwidth, and center frequency.
• Shelving type Bass and Treble controls.
All connections established in the previous procedure still apply to the surround equalization
alignment. Confirm that the microphone is in the position defined on page 5.6. Ensure
that format 04 is selected.
Note: The Cat. No. 441 can be configured for either Mono or Stereo surround operation using link
J3 ( See page 2-5 for details). If Mono operation is selected then an identical signal will be fed
to both Ls and Rs outputs in all formats. If only one power amplifier is to be used for the surround
channel then the Ls should be used. If more than one surround amplifier is to be used, both
outputs may be used to feed, for example, balcony and ground floor. The separate level controls
and equalizers may then be used to compensate for differences caused by the different acoustic
environments of the two areas. If stereo operation is selected a stereo surround signal will be fed
to the surround channels when format 10, Dolby Stereo SR
• D is selected.
If the surround speakers are wired for stereo operation or both surround outputs are in use
switch off (or disconnect the input to) the right surround amplifier or amplifiers.
Turn on the S switch on the Cat. No. 85C pink noise generator. Be sure that format 04
is selected.
Adjust the Ls ( left surround) gain control on the Cat. No. 242 B-Chain card for a sound
pressure level of approximately 85 dBC in the theatre. If only one surround output is used
set the level to 88 dBC.