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Author Topic: Preview Whirr...
Andrew Bangs
Expert Film Handler

Posts: 148
From: Kerrville, Texas, United States
Registered: Sep 2008


 - posted 11-01-2008 10:58 PM      Profile for Andrew Bangs   Author's Homepage   Email Andrew Bangs   Send New Private Message       Edit/Delete Post 
Hello... I have an interesting case of a whirring noise but only during particular Previews. I am assuming this is the preview and not the projector although it could be a combination of both as we just noticed this problem and we just moved it to a new projector. Any Ideas??? Can this develop while the print is being run over two to three weeks?

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Monte L Fullmer
Film God

Posts: 8367
From: Nampa, Idaho, USA
Registered: Nov 2004


 - posted 11-01-2008 11:02 PM      Profile for Monte L Fullmer   Email Monte L Fullmer   Send New Private Message       Edit/Delete Post 
Any specfic areas of the machinery that you can pinpoint this "whirring" noise to?

Kinda need more specifics to help you out on this one. Sorry...

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John Wilson
Film God

Posts: 5438
From: Sydney, Australia.
Registered: Dec 1999


 - posted 11-02-2008 03:03 AM      Profile for John Wilson   Email John Wilson   Send New Private Message       Edit/Delete Post 
Does it sound like the sprocket holes catching on the sprockets?

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Andrew Bangs
Expert Film Handler

Posts: 148
From: Kerrville, Texas, United States
Registered: Sep 2008


 - posted 11-03-2008 12:23 AM      Profile for Andrew Bangs   Author's Homepage   Email Andrew Bangs   Send New Private Message       Edit/Delete Post 
Ok sorry I meant that their is a whirring noise comming through the speakers.

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Andrew Bangs
Expert Film Handler

Posts: 148
From: Kerrville, Texas, United States
Registered: Sep 2008


 - posted 11-03-2008 12:24 AM      Profile for Andrew Bangs   Author's Homepage   Email Andrew Bangs   Send New Private Message       Edit/Delete Post 
But now that you mention it I have noticed a buzzing coming from the Dampening Sprocket. not on this particular film but on others that also comes and goes with different previews. Sometimes If I squeeze the clamp on the Dampening sprocket I can get the noise to go away and I also see the film shift it's tracking laterally by a minute amount. but I never see any film dust in the projectors so I know it is not scratching the film. I figured just bad film.

P.S. sorry for the double post... My connection has been funky lately.
[dlp] [bs] [dlp]

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Monte L Fullmer
Film God

Posts: 8367
From: Nampa, Idaho, USA
Registered: Nov 2004


 - posted 11-03-2008 12:54 AM      Profile for Monte L Fullmer   Email Monte L Fullmer   Send New Private Message       Edit/Delete Post 
Are we talking about the sprocket after the INT sprocket, or the final holdback sprocket after the scanner drum?

K, sounds like the sprocket itself is beginning to have hooking problems as the base of the teeth. Any way to take the sprocket out and reverse it to begin the wear on the opposite side of the teeth?

What kind of platter system do you have?

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Richard Hamilton
Phenomenal Film Handler

Posts: 1341
From: Evansville, Indiana
Registered: Jan 2000


 - posted 11-03-2008 03:13 AM      Profile for Richard Hamilton   Email Richard Hamilton   Send New Private Message       Edit/Delete Post 
Andrew,
I just had a nice long conversation with the projector company in Harbin and your theater came to mind. We decided that your problems are not equipment related, but rather operator error [Razz] Just kidding. She was interested in hearing about your problems.

What sound format are you playing your trailers in?

Rick

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Mark Strube
Master Film Handler

Posts: 322
From: Milwaukee, WI, United States
Registered: Feb 2007


 - posted 11-03-2008 11:50 AM      Profile for Mark Strube   Author's Homepage   Email Mark Strube   Send New Private Message       Edit/Delete Post 
It this in a DTS or a DD house? (Or neither? Both?)

If it's DTS, have you monitored the DTS player to see if the whirr happens when a given trailer must run in SR or SRD?

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Michael Brown
Phenomenal Film Handler

Posts: 1522
From: Bradford, England
Registered: May 2001


 - posted 11-03-2008 02:30 PM      Profile for Michael Brown   Email Michael Brown   Send New Private Message       Edit/Delete Post 
It could be an SRD house where everything is fine in digital but the SR is picking up the DTS track.

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Monte L Fullmer
Film God

Posts: 8367
From: Nampa, Idaho, USA
Registered: Nov 2004


 - posted 11-04-2008 12:46 AM      Profile for Monte L Fullmer   Email Monte L Fullmer   Send New Private Message       Edit/Delete Post 
True, he does have basement SRD readers attached to that thing. It's quite easy for a lateral guide to come out of adjustment just a hair and the optical reader picking up that timecode.

If he can do the adjustment to that lateral guide, any loop of film with DTS timecode can act like buzz track in a way - for one side can be the audible uneven squall buzz of timecode and the other side can be the steady sprocket buzz.

It's a band-aid fix if one doesn't have any genuine buzz track test film.

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Andrew Bangs
Expert Film Handler

Posts: 148
From: Kerrville, Texas, United States
Registered: Sep 2008


 - posted 11-04-2008 12:57 AM      Profile for Andrew Bangs   Author's Homepage   Email Andrew Bangs   Send New Private Message       Edit/Delete Post 
quote: Richard Hamilton
What sound format are you playing your trailers in?
Rick,
We are trying to run everything in Dolby digital but this particular projector (along with two or three others) is playing in Reverted Optical (aka Analog). The problem only occurs when the sound is reverted but for all the previews the sound is reverted only a couple have the Whirr. We have tried to re align the digital head as best we can however without the proper equipment it is a Crap shoot. It used to be as easy as looking for the Green LED on the camera mount but those have long since been responsive. Yet we can still have digital output. Just the other day a reader that usually pops between Digital and Analog due to faults in the digital around 6/7 (without any adjustment) was reading digital with 1/2 faults which I have never seen here (usually around 3/4). But still the LED on the Camera Mount was red. I am to the point of calling in a witch doctor because this just looks like VooDoo to me. Any help you can pass our way would be most appreciated.

I love movies and I love the movie experience which is what I want to share with the people of our city. But every sound flip, stoppage, Brain wrap, Flicker of the screen just tears my heart as I have to go in and say I am so Sorry to these people that their Movie experience was ruined.

quote: Mark Strube
It this in a DTS or a DD house?
It's a DD.

Monte we are using Horizon Platters. Right now however Two are down and we have some old Strongs replacing them but the problems are consistent. right now our plan of attack is Getting all the platters up and running. then we are going to tackle sound issues. In the Mean time I am just looking to get a head start on diagnosing the issues so later the fixes will come with less wasted time on trouble shooting. and if their is something simple that can be done in the short term well then I will do it. Thanks for the suggestion of flipping the sprocket I think I can do that. I will run a test and let you know.

Again thank you all for the response. This has truly been an invaluable resource for for me. [thumbsup]

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Monte L Fullmer
Film God

Posts: 8367
From: Nampa, Idaho, USA
Registered: Nov 2004


 - posted 11-04-2008 01:54 AM      Profile for Monte L Fullmer   Email Monte L Fullmer   Send New Private Message       Edit/Delete Post 
quote: Andrew Bangs
we have some old Strongs replacing them
At least, those STRONG A(P)3 units are simple to operate and they can be very dependable.

quote: Monte L Fullmer
one side can be the audible uneven squall buzz of timecode and the other side can be the steady sprocket buzz.

..and forgot to add that when you don't hear any one of these two sounds, you're pretty well dead center of the optical track.

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Michael Brown
Phenomenal Film Handler

Posts: 1522
From: Bradford, England
Registered: May 2001


 - posted 11-04-2008 08:42 AM      Profile for Michael Brown   Email Michael Brown   Send New Private Message       Edit/Delete Post 
quote:
We are trying to run everything in Dolby digital but this particular projector (along with two or three others) is playing in Reverted Optical (aka Analog). The problem only occurs when the sound is reverted but for all the previews the sound is reverted only a couple have the Whirr.
This does sound like it could be picking up the DTS timecode, if some trailers have the "whirr" and some don't, then some trailers have timecode but some don't.

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Andrew Bangs
Expert Film Handler

Posts: 148
From: Kerrville, Texas, United States
Registered: Sep 2008


 - posted 11-05-2008 01:46 AM      Profile for Andrew Bangs   Author's Homepage   Email Andrew Bangs   Send New Private Message       Edit/Delete Post 
I think I may have figured out some of the problem today. Their is a rocker arm that straddles the sound drum and while readjusting it today for the umpteenth time I noticed the film was tighter to one side than the other so I removed the Arm completely and the two arms were not parallel to each other. A quick squeeze and they were back in alignment (at least to the naked eye). I then replaced it and the film ran smooth. Unfortunately after that it did not run the rest of the night (as no one bought to it) so I will have to wait and see what happens the next time it runs. I am just keeping my fingers crossed on this one.

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