Dolby
®
Model CP650 Installation Manual
C-1
Optical Surround
Delay
> xxx mSec
Optical Surround
Level Trim
>xxx dB
Appendix C
Optical Surround Level Trim
Use this procedure to subjectively balance front and surround loudspeaker levels
using the Cat. No. 151B test film. The film contains band-limited noise, restricted to
the range 500 Hz to 2 kHz. The noise is cycled between the front center speaker and
rear surround speakers. The surround level should have already been set using the
final output level calibration procedure in Section 4.7.6.
1 2 3
7
4 5 6
8
Ensure that DIP switch 6, located on the setup
control panel, is in the “up” position.
menu
OK
Temporarily set the optical surround delay to
minimum (20 ms). This step eliminates any
confusion while the test film noise cycles between
front and rear speakers.
Press and hold the left menu button while rotating
the front-panel knob to step the menu to
Optical
Surround Delay
.
“20 mSec”
OK
Note:
If the optical surround delay has been set during a previous
CP650 system setup, write down the current delay setting
displayed!
Rotate the front-panel knob counterclockwise to
set the delay to 20 ms. Then press the OK button
to save the setting.
menu
OK
Press and hold the left menu button while rotating
the front-panel knob counterclockwise until the
Optical Surround Level Trim
menu appears.
Thread and play a loop of the Cat. No. 151B test
film.
