Sony DFP-R3000 Quick Start Manual page 16

The surround channel delay can be set with elaborate science based on SMPTE 202M.
However, an easy rule-of-thumb approach is to set the milliseconds of delay for optical
sources (via the AUX input) to equal the length of the theatre (in feet) + 10. For digital
sources (SDDS) it should be set to 60% of the optical surround delay.
Note: If the surround delay is already activated in the central cinema processor, disable
the surround delay for the AUX input.
14. To set the surround channel delay
and enable it for each input, bring up
the Preset Configuration screen by
selecting the Preset Configuration
option under the Presets item in the
main screen menu bar. This screen
allows you to select each Preset/Input,
make a level trim (to balance the
relative level of each Preset), set a
surround delay, and set the subwoofer
low pass filter (LPF) frequency for that
Preset.
15. To adjust the synchronization
between optical and SDDS playback,
access the Master SDDS Settings
screen by selecting Master SDDS from
the Master item on the main screen
menu bar.
Set the coarse adjustment of frame
offset by counting the actual frames of
film between the projector's film gate
and the LEDs of the DFP-R3000 Reader.
It should be at least 32 frames. The
system is temporarily muted if this
adjustment is done while the film is
running.
16. Now open the hinged front panel of
the DFP-2500 by removing the four
screws and then holding the front panel
at the right and left, pulling it in the
direction indicated by the arrows (1).