Audio question for projectionists
Posted 02 August 2011 - 05:00 AM
I went to see The Tree of Life one last time before it leaves theaters today. Just like last time, but at a different theater, there was a massive audio issue. This time not only did it sound like one of the speakers were blown but, and this is my main point in posting, the surround sound was off. So once again a film of this quality level was reduced to a couple of speakers, with light warbling on top of that.
So specifically, why does the surround sound not play in 40-60% of the film-based theaters I have been to in the last few years? Why can't it be turned back on after I complain each time? Why is there even the option to have it off, ever?
Posted 02 August 2011 - 05:41 AM
If the optical sound reader head is not correctly set up (incorrect focus, incorrect position, incorrect gate-to-reader spacing, ageing or improper lamp, etc) then it can affect reproduction to the point where the Dolby A phase encoding fails to work, or just produces occasional snatches of strange warbling sounds. Particularly, almost all modern prints use cyan dye soundtracks which require red LED illumination, because this allows the use of a less environmentally disastrous chemistry during processing. Attempts to read these soundtracks with old-style incandescent sound heads can cause these problems, although usually it will be completely unlistenable in that scenario.
Why is there the option? Well, we were a facility used by a film club, as well as running our own programme of less-known, though still commercial, features. This exposed us to a lot of things that first-run facilities very seldom see, like full-frame Academy prints with mono variable-density soundtracks, for which we had appropriate backing plates, lenses and screen masking, and of course switched the Dolby audio system to "Mono". If you fail to do so, the desirable tendency of a variable-density soundtrack to average out pops and clicks caused by dirt is lost, and particular audio content may cause the Dolby A decoder to do odd things. But then, we cared, and we knew we were catering to an audience of people serious enough about cinema to join a film club. They would certainly complain if things were not done correctly.
Posted 02 August 2011 - 07:04 AM
Theater sound systems are divided into two parts:
The first is the "A" channel which is everything required to read the analog or digital soundtrack off the print, decode it if a digital track (Dolby Digital, DTS, or Sony SDDS) or dematrix and decompress it if a Dolby A or SR analog optical track. Ideally all the output of all of them is at a standardized audio level.
The "A" channel is followed by the "B" channel which is everything associated with level control, equalization, power amplification, and speakers for a given house. When a house is "tuned" by Dolby or THX what they are doing for the most part is adjusting the "B" channel. All they should have to do with the "A" channel is adjust the mechanical and electronic adjustments directly involved with the soundtrack reader(s).
Dolby Digital systems are designed to automatically fall back to the analog optical soundtrack if the digital system isn't working or has too many errors (I believe DTS and Sony do the same thing). Given what you've described, I strongly suspect the problem with the house that was playing "Tree of Life" was extremely poor maintenance of both the "A" and "B" channel. Loss of full surround and so-so sound quality hints at "A" channel issues where the system had fallen back to the analog SR track (all modern prints have a Dolby SR track on them) and the optical reader wasn't set up correctly either. Given the house's crappy attitude about maintenance the "B" channel could very well been misadjusted and had a busted speaker as well.
I speak with some knowledge, I've got a home theatre setup out in my shop with a Dolby Digital system using a CAT 702 reader and a DA-10 digital decoder and an analog CP-55 modified for split surround. My projector is a Simplex SP portable with an LED and stereo solar cell optical track reader.
By the way, a properly set up Dolby SR sytem can sound very good, it's noise reduction and audio processing math is very similar to the math underlying digital audio like MP2/MP3, etc. Ray Dolby is one smart cat.
Posted 04 August 2011 - 05:05 AM
That theater would be an ideal place for some serious camera comparisons. Sony or RED should rent one out for a night and invite a bunch of Directors and DP's.
Posted 04 August 2011 - 12:38 PM
Sorry, I am going to have to call bullsh** on this one. Because some sound rack was improperly installed or some minimum wage, untrained vidiot up there twittering on his iPhone 4 instead of marvelling at the 20+ miles of precision 35mm film dancing all around them has dropped the ball, you're going to blame the FILM for the problem?
Don't blame the 2K masters used to make film prints either.
You sound like Dolby Labs. Because every step of the mastering process in the photo-chemical workflow has been compromised, that somehow proves that a 4th generation 35mm print on '83 or '14 (either of which can easily be able to resolve 4K, encode the latest, greates 25 channels of mixed stereo sound with 10 subwoofer channels) is the problem.
I won't even comment on sound. Sorry if this is your line of work, but sound is in all ways secondary to the visual experience. Movies existed long before synchronous sound was even perfected. I like a good score as much as anyone, but most movies are recorded MONO, with one boom mike. All the "surround sound" "stereo sound" is artificially mixed together. Not that I would like being in a mono house with muddy sound, but I still cannot understand people who go to movies for the audio first, seemingly.
That'd be like going to a rock concert with the costume design anywhere but at the front of my mind.
I don't advocate throwing anyone anything under a moving bus, but if you are going to do it anyway, make sure you throw the RIGHT thing under the bus. Don't throw the baby out with the bathwater.
Posted 04 August 2011 - 02:31 PM
My experience isn't just an audio problem. I continue to see severe registration and focus problems. The fact is that 35mm projection no longer works on a national (or international) scale. I don't care what is at fault, only what the solution is. In this case 4K digital projection is the only solution I see. You can cry all you want but that isn't going to transform the hiring, training and maintenance practices of thousands of theaters. Not all theaters can be Arclights, which do a good job at film projection.
I'm as frustrated as anyone when it comes to film's issues. I personally like the experience of film more than I can explain here and Im a die-hard, dedicated fan of it but it's mostly over now and we have to accept that. This is similar to my other post about labs needing to cut their rates. I felt very strongly that the last indie feature I was involved with should be on 16mm and spent days trying to make it work budget wise, but using an F3 saved them over $10,000 in the end because of the scanning costs, so that was it.
This will continue, and as theaters keep getting complaints that a BluRay is a much better viewing experience, digital projection will be in order, just not fast enough. If not they will suffer till closing. If you could see the Muvico, on a Tuesday night, you'd see what a difference it makes. It was crowded and this is because, in part, it is an almost perfect viewing experience. The layman feels the difference.
Posted 04 August 2011 - 02:44 PM
I won't even comment on sound. Sorry if this is your line of work, but sound is in all ways secondary to the visual experience. Movies existed long before synchronous sound was even perfected. I like a good score as much as anyone, but most movies are recorded MONO, with one boom mike.
For one, Karl, sound is much more difficult to acquire nicely on a movie set than visual ever is. I know this is Cinematography.com and all but this is a true point. Visual is about light and shadows and if the camera doesnt see it, it doesnt exist. Unfortunately the same cant be said for audio. Audio knows ALL. And as bad as it is to try to capture location sound, you also have to deal with many amateurish Directors who greenlight the DPs to set up any ridiculous shot they want while making the Production Sound Mixer (who is technically equal in rank with a DP, being a department head) deal with having to squeeze in there to get great sound without regard of the crappy situation or in some cases even noisy cameras and lights(some flo's) or even something as silly as having the AC on indoors because the crew is hot from all the lights! Seriously, if a DP was as disrespected and put in as absurd of situations as a sound mixer, most would quit.
And one last point, Karl...what can make MOST people walk out of a theater quicker if it is poor? Nuff said...
Posted 04 August 2011 - 05:58 PM
Did you read the title of this thread? Film projection is now useless due to poor quality. IDK how that has anything to do with the 35mm print. It has to do with poorly maintained ELECTRONIC components, not the photomechanical, reliable, components that have remained remarkably similar to what was brought about in the very beginning of photographic sound.
Blown out mono sound? Not the film's fault.
How is digital going to in any way eliminate technical issues? It is just as easy to crank a sound rack all the way up to 10 and blow out all of the speakers with a hardrrive as it is with a 35mm projector and a platter.
Posted 04 August 2011 - 06:40 PM
So as much as I love film, I look forward to the day when some technology (digital, analog, or chemical) can simplify the workflow, cost, and time for indies without compromising the allure of film.
Posted 04 August 2011 - 07:54 PM
And the theater knew it. They just didn't care. They even tried to refuse my refund (I walked out after ten minutes) but gave in once they realized I knew more than them.
Sound is constantly screwed up at theaters I attend. But the problem of the screen being too damn dark is much much worse.
Posted 04 August 2011 - 08:14 PM
Posted 05 August 2011 - 02:08 AM
How is digital going to in any way eliminate technical issues?
Well, it does seem to solve almost all the issues. I think you know that.
This thread is about film projection issues. Film based acquisition is another story and will hopefully be around for many years.
Posted 05 August 2011 - 03:26 PM
How is ill-maintained film equipment somehow magically going to replaced by not-ill-maintained digital equipment?
If anything neglect will be far MORE costly, because digital (this is a generalization, but a pretty accurate one) either works or it doesn't.
The myriad of issues that plague getting a soundtrack off of film through tangles of wires, cards, readers, and speakers will be multiplied tenfold when it is ALL electronic and there is a far higher tech (therefore far more easily broken) replacement for it.
Posted 05 August 2011 - 05:12 PM
Since the sound racks are the SAME for digital projectors
Only up to a point - there's a lot of gear in a 35mm projector for reading any of three types of sound-related information, all of which are essentially analogue devices which require alignment and maintenance.
I would suspect that the audio comes out of the media block largely intact, at least, with a digital setup. It does remove some variables.