Installation manual

Dolby
®
Model CP650 Installation Manual Final Adjustments
7-5
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Reader Delay
> xxx Perforations
Table 7–2 Surround Delays Based on Theatre Dimensions (in Meters)
Width (meters)
10 15 20 25 30 35 40 45 50
10
20 20 20 20 20 20 20 20 20
15
20 20 20 20 20 20 20 20 20
20
30 30 30 30 30 30 30 30 30
25
40 40 40 40 40 40 40 40 40
30
50 50 50 50 50 50 50 50 50
35
60 60 50 50 50 50 50 50 50
40
80 70 60 60 60 60 60 60 60
45
90 80 70 70 70 70 70 70 70
50
100 90 80 80 80 80 80 80 80
55
110 100 90 90 80 80 80 80 80
60
120 110 110 100 90 90 90 90 90
65
130 120 120 110 100 100 100 100 100
70
140 140 130 120 110 110 110 110 110
Length (meters)
75
150 150 140 130 120 120 110 110 110
7.4 Setting Dolby Digital Reader Delay
On a Dolby Digital print, the digital sound data is located 6 frames in advance of the
analog soundtrack, and 26 frames in advance of the picture. When the digital
soundhead is mounted above the analog soundhead (as with the Cat. No. 701), a delay
is necessary to synchronize the digital soundtrack with the analog track and the
picture. In the CP650, this delay is set by entering the number of film perforations,
within the range from 12 perfs (approximately 160 ms delay) to 512 perfs
(approximately 5 seconds).
Soundhead delay can be determined in either of two ways—static or dynamic— as
described below:
Static
1. Thread a length of Cat. No. 1010 Digital Soundhead alignment test film such that
the “bullet” frame (perf 106) is located in the picture gate, and perf number 26 is
located at the analog soundhead.
2. With the length threaded through the Cat. No. 701 Digital Soundhead, read the
number of perforations present in the light path of the digital soundhead. Enter
this number using the procedure shown below:
Press the left menu button to move to the Dolby
Digital Reader Delay menu.
= xxx Perfs
OK
Rotate the front-panel knob to show the number of
perforations obtained above, then push the OK
button.
3. Verify the accuracy of the setting by running a loop of Cat. No. 1010 test film and
observing that the flash on the screen coincides with a pip in the sound.