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» Film-Tech Forum   » Operations   » Digital Cinema Forum   » What goes wrong in digital cinema? (Page 1)

 
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Author Topic: What goes wrong in digital cinema?
Harold Hallikainen
Jedi Master Film Handler

Posts: 873
From: Denver, CO, USA
Registered: Aug 2009


 - posted 09-12-2014 10:58 AM      Profile for Harold Hallikainen   Author's Homepage   Email Harold Hallikainen   Send New Private Message       Edit/Delete Post 
I'm preparing a presentation on digital cinema quality control. I'd like to hear comments from people on what sort of stuff they typically find has gone wrong when doing a maintenance check of a theater. I'm thinking of things like failed speaker drivers, stolen speakers, rattling speakers, high noise level, low luminance, color shift, etc.

What sort of stuff do you find during a maintenance visit, especially stuff that has not yet been reported by patrons?

THANKS!

Harold

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Jim Cassedy
Phenomenal Film Handler

Posts: 1633
From: San Francisco, CA
Registered: Dec 2006


 - posted 09-12-2014 11:09 AM      Profile for Jim Cassedy   Email Jim Cassedy   Send New Private Message       Edit/Delete Post 
biggest problem with digital cinema:
The 35mm projectors are gone!

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Harold Hallikainen
Jedi Master Film Handler

Posts: 873
From: Denver, CO, USA
Registered: Aug 2009


 - posted 09-12-2014 11:15 AM      Profile for Harold Hallikainen   Author's Homepage   Email Harold Hallikainen   Send New Private Message       Edit/Delete Post 
And, of course, that was noticed during a QC check!

THANKS!

Harold

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Buck Wilson
Jedi Master Film Handler

Posts: 882
From: St. Joseph MO, USA
Registered: Sep 2010


 - posted 09-12-2014 11:28 AM      Profile for Buck Wilson   Email Buck Wilson   Send New Private Message       Edit/Delete Post 
Maintenance check like from a technician visit or just daily troubles?

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Frank Cox
Film God

Posts: 2160
From: Melville Saskatchewan Canada
Registered: Apr 2011


 - posted 09-12-2014 11:52 AM      Profile for Frank Cox   Author's Homepage   Email Frank Cox   Send New Private Message       Edit/Delete Post 
Stolen speakers? *boggle*

How in the world do you steal speakers from a theatre without someone noticing?

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Dave Macaulay
Film God

Posts: 2278
From: Toronto, Canada
Registered: Apr 2001


 - posted 09-12-2014 12:02 PM      Profile for Dave Macaulay   Email Dave Macaulay   Send New Private Message       Edit/Delete Post 
How to steal speakers:
1) take some tools and go to a late show movie
2) After the movie when everyone leaves during the credits, go behind the screen, wait for staff to leave and lock up (or just do it during the movie if you dare)
3) remove speaker driver
4) go out emergency exit

It's not actually unusual: sub drivers, main channel drivers, horn drivers all disappear but the sub drivers are the popular target.

Complete cabinets rarely go but it's happened. Someone can hide behind a screen quite easily and unless there's an alarm tripped they have until morning to do as they wish.

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Gavin Lewarne
Master Film Handler

Posts: 278
From: Plymouth, UK
Registered: Aug 2009


 - posted 09-12-2014 12:03 PM      Profile for Gavin Lewarne   Email Gavin Lewarne   Send New Private Message       Edit/Delete Post 
During my normal routine maintenance, I removed of the plastic side covers (the lamphouse one) and found a big ass spider in there guarding a blob of spider eggs. How they had not been cooked I don't know, and they hadn't been in there long as I clean the filters every 2 weeks.

I safely transplanted them to my basement room.

Does that count?

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Harold Hallikainen
Jedi Master Film Handler

Posts: 873
From: Denver, CO, USA
Registered: Aug 2009


 - posted 09-12-2014 12:30 PM      Profile for Harold Hallikainen   Author's Homepage   Email Harold Hallikainen   Send New Private Message       Edit/Delete Post 
Thanks for the comments! I guess I'm looking for stuff noticed by theater staff, whether by a tech on a maintenance check or by a manager who notices terrible sound or picture.

I used to work in broadcast. I've seen stations taken off the air by various animals crawling into equipment to get warm and not surviving.

Harold

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Marco Giustini
Film God

Posts: 2702
From: Reading, UK
Registered: Nov 2007


 - posted 09-12-2014 02:09 PM      Profile for Marco Giustini   Email Marco Giustini   Send New Private Message       Edit/Delete Post 
I'd say number one is: misaligned/badly installed lamps.

Then
Amplfiers' gains which get dirty and stop working/lower the output
Horns got loose and pointing to the ceiling/elsewhere
porthole windows which have never been cleaned before

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Carsten Kurz
Film God

Posts: 4207
From: Cologne, NRW, Germany
Registered: Aug 2009


 - posted 09-12-2014 03:54 PM      Profile for Carsten Kurz   Email Carsten Kurz   Send New Private Message       Edit/Delete Post 
We had a 'classic' 35mm setup with CP65/DA20, QSC USA amps and JBL speakers.

When we installed our digital system, we ran into trouble when we tried to calibrate the surrounds. It turned out that some of the 10 JBL 8330 we had in a 5 each LS/RS config had their 508G woofers blown. They were essentially dead on low volume signals, but rattled like mad on higher volume signals. We were puzzled because we didn't understand when this happened and for how long this was going on before we did the digital install and noticed it. With the install, we also split them into 3/2 groups for 7.1 to be fed from a 4ch amp.

We couldn't solve the issue with the blown speakers during the installation because we had no spare speakers at hand. We configured a high pass filter on the AP20 for all surround speakers and decided to finish the install. The filter did not let lower frequencies through so the rattle did not occur. It sounded a bit 'phony', but it was a decent workaround.

We then sourced replacement speakers and prepared a check run on all surrounds to identify those with defect woofers. That wasn't as easy as I thought because they were wired in parallel in a wall box and it wasn't easy to get access to all individual speakers with test signals.

Simply listening from the auditorium would not reveal the problem with individual speakers because the adjacent working speakers would mask the missing low frequency at lower levels, and localization was nearly impossible when the rattling occured at higher levels.

We then actually resorted to placing an amp in the auditorium with a long speaker cable and wiring every speaker individually from a ladder with the test signals and listening from close. We were again puzzled to find out that from 10 surround speakers, only three had their woofers still working!

We replaced all those defective woofers, but never learned for how long we were already running with such a mediocre setup. Nobody could remember the rattling to have occured ever during screenings before. Either all those defects occurred during the digital installation due to a wiring or amp error. Or the 35mm DD mixes never carried enough low frequency level to trigger it.

Whatever - we were running this 7.1 setup then for over a year without any issues.
Recently I noticed during a regular maintenance check that all RS speakers were dead. I rewired inputs and outputs of the 4ch amp and it turns out the fourth channel of that amp is dead. At the same time I noticed that one of the LS speakers also was not working (all wired in parallel now). I climbed up the ladder and found the + wire had slipped out of the clamp...

Heck, and again I had no idea for how long this was already going on. Usually during 5.1 presentations, the BSR speakers would back up the missing RS, and one of three/five missing LS/BSL did probably not cause to much irritation anyway .

Harold, if you are looking for a future USL product, a simple way to check/rewire parallel/series wired surround arrays would really help to conduct more frequent equipment checks. We never had issues checking front systems and subwoofer, but these issues with the surrounds really struck me. I am not on-site daily, but often enough to be able to notice that kind of problem early.

Pre-digital, we had two identical issues with our front L/R system's crossover, had to resolder the circuit board to get the HF back.

Other than that, we had a few issues of ordered DCPs arriving, but not their KDMs, and always asked myself what kind of system these distributors operate that allows drives to be ordered, but missing out KDMs for them.

We have reoccurring issues with pre-show content associated with the general use computer this is running from.

We never experienced any DCI/sound equipment failure, never missed a single automation cue (all GPIO wired). A few ingest drives had issues, but we never had lost shows due to that.

We did lose a show due to a bad processing board in our Sony, but it was replaced within one day even though we were not on a support contract.

A lot of CPLs/packages are named badly wrong against DCNC.

Trailers are still mixed too loud, but with playlist based volume control this is no big deal, we play trailers at 4.5 and features at 5.5 to 6.

BluRays and DVDs are still a nightmare to be presented by 'ordinary' staff properly. But I'd say this is a training issue, if we'd do it more often, they would get used to it.

- Carsten

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Steve Matz
Jedi Master Film Handler

Posts: 672
From: Billings, Montana, USA
Registered: Sep 2003


 - posted 09-12-2014 04:27 PM      Profile for Steve Matz   Email Steve Matz   Send New Private Message       Edit/Delete Post 
quote:
biggest problem with digital cinema:
The 35mm projectors are gone!

I just don't understand a lot of these Theater owners
taking their 35mm Projectors/Equipment to the Dump. I know when a person is strapped for space that can become an issue; but it just boggles my mind that you would take a perfectly good running projection system to a Landfill. I'm sure their are private home collectors that would of gladly taken the equipment off their hands. Just like our local drive-in here; as soon as the Digital Equipment arrived; off went the perfectly good running CENTURY Equipment to the Dump.I would have taken that Stuff in a second if I had known what he was going to do.

I guess maybe I'm from the generation that you don't throw perfectly good running things in the Trash just because they have been superceded by something newer or higher Tech. When the FORD Model A came out, I don't think too many Model T owner's took their less superior T's to the Dump. There are still 1000's of 35mm Films out there; I don't see them all getting chopped up or destroyed. Before you throw your perfectly good 35mm Projectors in the Garbage you might want to make a Phone call or two and find someone that really wants/cares to have this valuable equipment...

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Buck Wilson
Jedi Master Film Handler

Posts: 882
From: St. Joseph MO, USA
Registered: Sep 2010


 - posted 09-12-2014 04:54 PM      Profile for Buck Wilson   Email Buck Wilson   Send New Private Message       Edit/Delete Post 
I was appalled when I found they scrapped all our equipment. 8 year old Strong Super Hilite II/Simplex Apogee/Strong AP3 combos. 8 YEARS OLD. 10 setups.

Upon the conversion, I had very painstakingly and meticulously folded up all the platter stands, stacking them very neatly with all the projectors lined up out of the way at the end of the booth. It took me days. I had planned on purchasing at least one full set up at some point in time when they wanted to get rid of them.

They sat there for a year or so, until Regal came along, and one day I came in for my shift and my boss snidely says "Did you get an empty feeling when you went upstairs?" I hadn't been up there yet but knew instantly what he was talking about.

He detailed the crew that came in, literally ripping everything apart; doors off the projectors, rectifiers out, heads off, platter stands apart, throwing everything into a box truck for scrap. There was shards, bolts, washers, etc strewn all about. I was literally heartbroken. WHYYYYY!??! I had threaded that eq daily for 5 years!! I'm still very upset about it. I could've used them at the other theater I worked at too. I would've bought all of them. But instead, they're soda cans now.

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Marcel Birgelen
Film God

Posts: 3117
From: Maastricht, Limburg, Netherlands
Registered: Feb 2012


 - posted 09-12-2014 05:06 PM      Profile for Marcel Birgelen   Email Marcel Birgelen   Send New Private Message       Edit/Delete Post 
Many companies have policies that don't allow written off equipment to be sold or given away, it has to be scrapped and actually destroyed. The reason is simple: This equipment could still be usable for the competition.

Now in this particular case, there would've been almost no use for any competitor, but that doesn't make a policy go away.

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Buck Wilson
Jedi Master Film Handler

Posts: 882
From: St. Joseph MO, USA
Registered: Sep 2010


 - posted 09-12-2014 05:10 PM      Profile for Buck Wilson   Email Buck Wilson   Send New Private Message       Edit/Delete Post 
Oh I know. Makes me sick to my stomach just thinking about it.

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Joe Elliott
Master Film Handler

Posts: 497
From: Port Orange, Fl USA
Registered: Oct 2006


 - posted 09-12-2014 06:03 PM      Profile for Joe Elliott   Email Joe Elliott   Send New Private Message       Edit/Delete Post 
I would agree with the lamp installed improperly, or not aligned. I have seen many that they never tightedend down the connectors, and depending on the size of the lamp, it arced and burnt up the connector.

Staff running projectors, even though there are errors, and not reporting them, because they were able to keep it running (overheat errors), until they have nearly fried the projector.

Missing channels on sound - most companies service contracts don't cover sound, and 35mm contracts used too. They have no one to check it anymore, so there is no one reporting it until the center has gone out. I have gone into theaters that have reported sound problems to find that only one channel was working. The rest had blown one by one for various reasons.

Destroyed reflectors, many companies are taking their chances with pushing bulbs beyond their warranties, and I am seeing an increase in reflector replacements. Now I don't know if that's what they report to the bulb companies, as I don't think any of the bulb companies ask for logs, yet . . .

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