Film-Tech Forum ARCHIVE: DTS Delay Setteing

This is topic DTS Delay Setteing in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=011024

Posted by Ram Sup (Member # 4711) on 09-09-2011, 12:03 PM:

HI..Everyone,

My projector head is strong millenium. I've install the DTS reader on top of a CAT702 reader. i'm using DTS-6. Now the sound does not sync. Can anyone guide me on what the delay setting is on DTS-6.

Posted by Sean Weitzel (Member # 244) on 09-09-2011, 03:16 PM:

all you have to do is thread a strip of scrap film through your digital readers down to the lens of the projector head. Mark the frame that is lined up with the LED pickup in the DTS reader and mark the frame that is in the gate of the projector. Pull the strip of film out and count the frames. Unscrew the blue cover on the front of the DTS 6 and you will find the offset adjustment. Set the adjustment to the number of frames you counted. One is for every 10 frames, and the other is single. for a 24 frame offset you would set the dials to 20, and 4. At this point, thread a reel with DTS content and start projecting it. You can adjust lip sync by adjusting the single frame adjuster until you are satisfied with sync. See page 4-3 to 4-4 in the DTS 6 manual in the manuals warehouse.

Posted by Randy Stankey (Member # 64) on 09-09-2011, 03:58 PM:

They make a target film for this purpose.

All you do is thread the film and put the "Start" mark (usually a star) next to the scanning point of the sound reader then look through the film aperture and read the number. Dial in that number and you have it.

I agree that it is best to run a test reel after you have made the adjustment to be sure the sound is in sync the way you want it to be. Even though the test film says it should be in sync, the way you thread the film can cause variance. Running a test ensures that you have threaded the film the way it's supposed to be but, if you have a good reason to thread differently (e.g. at rest but pre-pulldown versus post-pulldown) you have accounted for that difference.

You might also be able to eyeball (or, is that "earball") the sound into sync by playing a reel of film and adjusting till it's in sync but this should be reserved for emergencies only where test film is not available.

Posted by Manny Knowles (Member # 1171) on 09-09-2011, 06:25 PM:

Don't just count the frames.

DTS offset formula:

Count the number of frames between the LED on the reader and the projector aperture. Multiply by 1.25 and then subtract 1.

Then dial THAT number into the front of your DTS processor.

This is the procedure from the manuals. If you don't have a manual for your unit, you can download it from the "Warehouse" section.

(Does anybody know why it couldn't be as simple as counting the frames and dialing that number in??)

Posted by Brad Miller (Member # 2) on 09-09-2011, 10:23 PM:

Make a loop of a trailer with dialogue. The camera doesn't have to be on the person talking, you just want talking to come through your booth monitor. Run the loop and switch back and forth between dts and analog DURING the words. You will VERY quickly tell if you are off, and I find this method more accurate than doing it "by the book" because if there IS a dropout, there is less of a chance (assuming you have good SR) that the dropout will be noticeable.

Posted by Richard Hamilton (Member # 321) on 09-10-2011, 07:38 AM:

quote: Manny Knowles
Does anybody know why it couldn't be as simple as counting the frames and dialing that number in??

Haven't worked on too many DTS installs, but could it be the timecode is running at 29 non drop FPS?

Rick

Posted by Louis Bornwasser (Member # 3063) on 09-10-2011, 06:29 PM:

I like the old system with earbuds: one analog, one digital. Adjust for no echo. Louis

Posted by Joe Redifer (Member # 3) on 09-10-2011, 08:45 PM:

If you thread through the Dolby reader as well, I believe the delay is 69. Easy number to remember.

quote: Manneth
(Does anybody know why it couldn't be as simple as counting the frames and dialing that number in??)

Because DTS operates at 30fps instead of 24. They were a little retarded when they created DTS.

Posted by Gordon McLeod (Member # 33) on 09-10-2011, 09:47 PM:

No they were not retarted time code is based on video at30 fps (actually 29...depending on if it is drop frame)

Posted by Joe Redifer (Member # 3) on 09-10-2011, 11:15 PM:

Yes they were retarded because film is not videotape. Even so, the DTS unit could have been programmed so that it knows that every frame offset on the front of the unit as selected by the user = 1.33 timecode frames (or whatever the number is) and therefore you can have an actual reader to aperture frame offset. Just thread up any ol' leader, count the frames, dial it in and be done! They would have done this, but they had a little bit of the Down™ affecting their judgment.

Posted by Manny Knowles (Member # 1171) on 09-11-2011, 06:17 AM:

I like Brad's method a lot! [thumbsup]

Of course it requires consistency in setting the size of both upper and lower loops.

Now...if we could just fix the typo in the subject header.........