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Author Topic: XD10 - right offset, still out of sync Michael Schaffer "Where is the Boardwalk Hotel?" Posts: 4143 From: Boston, MA Registered: Apr 2002 posted 02-03-2006 10:05 PM                        I just came back from a location in Mexico which had complained about the DTS being out of sync in 2 screens. I checked the offsets which were at 14.5 and 32. Distance between the TC LED and the aperture is 21, not counting the frame right in front of the LED, so 21x1.25-1=25.25 on both systems. The offset values were obviously wrong. OK, no further questions at this point. We didn't test run a movie since we didn't have that much time, but I showed them how to finetune the sync if necessary. Back in the US, today I get a call it is completely out of sync. It did keep the setting I had entered. The print is "The Fog", original English version. But the same problem had been encountered with other prints. On the face of it, that doesn't surprise since the offset values were incorrect. But again, the print we have there is simply the same as the US version, plus subtitles. I am wondering if this is a known problem. Could it be that the unit simply does not accept the entered value and plays at the same offset no matter what? Firmware is .16, not the most recent one (.17), but I believe that version only addressed CSP issues.  |  IP: Logged Mark J. Marshall Film God Posts: 3188 From: New Castle, DE, USA Registered: Aug 2002 posted 02-05-2006 04:13 PM                    I don't know if this has any relation to the problem you're having or not, but for what it's worth, we had a similar problem with our XD 10 when we installed it over a year ago. The frames between the reader and the aperture were counted, the math was done as per the instructions, and the unit was set correctly, however when you went into the auditorium to listen to it, it was clearly wrong. We fine tuned it manually, and it's been running fine ever since. Much better than the warbling CP650 anyway.  |  IP: Logged Michael Schaffer "Where is the Boardwalk Hotel?" Posts: 4143 From: Boston, MA Registered: Apr 2002 posted 02-05-2006 08:13 PM                        Apparently the same problem. I am surprised no one else has replied yet.  |  IP: Logged Mike B. Smith Film Handler Posts: 82 From: Universal City Registered: Nov 2004 posted 02-05-2006 11:39 PM                     Over the years since the DTS-6 I have heard complaints about units being out of sync. Sync issues can be caused by a few things and many of the solutions depends on how much of the story you get over the phone or observe and hear for yourself. The primary cause is usually incorrect setting or threading of the film. There are two methods for calculating the offset, one is using the DTS offset film, and the other is the frame count method as explained in the earlier post by Michael. I also have experienced failures in the offset rotary switch used in the old DTS-6 and 6D that has caused sync problems, but the XD10 settings are done thru software not a contact type switch. Anything of course is possible. I would be very interested in hearing from individuals that feel they have corrected a sync issue by adjusting the setting very different from the calculations they obtained. I have been to many Theaters where they have combinations of DTS, Dolby, and SDDS heads all mounted in different positions and locations on the same projector. It’s interesting to see how these are set up, some run thru all heads others run only thru the head they are using; then again some run thru two and not the other. In any case I hope you understand what I’m getting at; it’s possible to thread out of sync if you don’t know how the film was threaded when the calculations were made. Many Theaters have a threading diagram to show film path through the different systems. When checking for sync if you have limited time and don’t want to purchase the DTS Bill & Buzz test print, or wait to play a feature to check for sync, there is a no cost version available at most any Theater that runs DTS trailers. Take an old trailer with DTS timecode that has a good section for sync noise, dialog, etc, splice this into a loop. Grab the old DTS trailer disc that contains the audio. Do the frame count method to obtain the first setting then run you test loop and adjust if necessary. If your fortunate (or unfortunate depending on your point of view) to have a DTS-6AD you can match the analog with the digital and set sync very precisely by pressing and holding down the “AMPS” and “C” button on the monitor panel. Adjustments can be made to the sync while listening to the digital and analog sound at the same time. Getting back to the original question, it's difficult to give an answer since some questions still exist. Did they understand your explanation on how to adjust sync when you showed them? Did someone change this since you left? Can someone there verify the sync settings? Is it possible they threaded differently? Are they running other materials that may be out of sync?  |  IP: Logged Michael Schaffer "Where is the Boardwalk Hotel?" Posts: 4143 From: Boston, MA Registered: Apr 2002 posted 02-05-2006 11:51 PM                        The setup is very easy: it is a TC reader on a Christie projector, no other readers, no alternative threading paths. I did explain how they could finetune later, but they didn't change the settings from what I had entered before they ran the first show the next day, and then they called me before trying anything. I had the manager who had been there with me the night before - she is a very reliable person, BTW, so I am pretty sure she didn't tinker with anything - doublecheck the settings, they were still the same as what I had entered. I had counted the distance three times. For the measuring, I used clear leader with an X which I threaded through TC reader and head, then slowly advanced until the X was exactly in front of the LED. Then I checked the loop size and finally took a marker and made an X on the film through the aperture. They had experienced the same problem with different prints. I had attributed that to the incorrect settings. I do not know if the installers who had last been there 3 months ago or so on a routine visit maybe entered those settings in an attempt to achieve sync. In any case, they didn't work. The print that was run the next day was the English OV of "Munich", so I think we can rule out an incorrectly encoded local version or something like that. In other words, the settings I entered, the threading path, the played films, all thaese check out, but the units still play out of sync with the rght settings. Is it possible that a faulty component on the TC board or another board can cause this? What I hadn't mentioned before because this appeared irrelevant to me is that the XD10s are hooked up to ECPs. I know very little about the latter - is it possible that the offset variation might be caused by these, is the B chain digital and could DSP problems cause these unwanted offsets? The optical sound played back by these ECPs has no problems. [ 02-06-2006, 01:17 AM: Message edited by: Michael Schaffer ]  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 02-06-2006 04:58 AM                     A dts reader on a Christie head should be 23-24 offset. BTW, an easy test I use for sync is very similar to what Mike suggested above with the 6AD. I simply toggle between SR and DIGITAL quickly every few seconds while playing a loop of strictly dialogue. If the switch back and forth is smooth, you are dead on. If it appears there is a skip or "blip", you are off (even if only by a perforation).  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 02-06-2006 01:18 PM                     If my memory serves me correctly, there is a function with the 6AD unit that if you go into the menu somewhere, and if you press two softkeys together, both the DTS and optical can be heard at the same time to see if the timecode and optical is in sync. I just haven't done this trick for a long time and have forgotten how to do it. I know you can do a similar with the Dolby units with headphones on the test points, but can't remember on the DTS Maybe, there is a function like this in the XD-10, but don't know since I'm not familar with this unit. -Monte  |  IP: Logged Mike B. Smith Film Handler Posts: 82 From: Universal City Registered: Nov 2004 posted 02-06-2006 02:23 PM                     I went into some more details to benefit anyone interested in the general subject, but the location you described is a basic set up with very little possibilities of errors. With the Timecode reader on top of a Christie, your calculations as described should be in the ball park and the results should not be reported as “completely out of sync”. This makes me think something more is in error. The DTS ECP will have no effect on digital delay. Unlike the DTS-6AD the XD10 is a “digital playback only” and does not compare optical to digital, Checking back on records one XD10 came in reported as drifting out of sync, nothing could be found wrong with the unit. Are all reels out of sync? You mentioned this is a subtitled print, I will have to verify the following but I believe normally in Mexico they overlay subtitles on existing prints but is there a possibility it was re-shot in a Mexico lab? Have someone look at the film leaders and see where the digital starts, leaders can be checked for optical and digital sync pop marks. Are all of these different prints out of sync the same? Are there any local theaters in the area that have the same print complaints? Can the print be brought into sync by adjusting the offset regardless of the calculation? Is there an electrical power issue at this site? I would suggest sending them a known good test source such as a used trailer with the audio disc so it can be ran there to verify your calculated offset.  |  IP: Logged

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