my profile | my password | search | faq & rules | forum home

» Film-Tech Forum ARCHIVE   » Operations   » Film Handlers' Forum   » Aligning Sound Heads (Page 1)

This topic comprises 4 pages: 1  2  3  4

Author Topic: Aligning Sound Heads Andrew Bangs Expert Film Handler Posts: 148 From: Kerrville, Texas, United States Registered: Sep 2008 posted 09-10-2008 12:52 AM                        Is their a special tool used for Aligning Sound heads accurately or is it done by eye and ear? I have a Dolby CP650 unit. in a Horizon Projector. Here is a rough picture of what it looks like. the top eye is the standard Analog and the lower one is the Dolby Digital.I can Loosen the light sending unit with an allen wrench then twist and pull it on the shaft but I am doing this by eye. in theory when the alignment is good their should be a green LED on the Dolby Eye. But no matter what I do I can't seem to get it to light up solid. I get it to flash on and off. but never solid. Is their something else I am missing?  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 09-10-2008 01:21 AM                     Aligning Dolby Dig readers take a loop of new roll of CAT-69 1kz tone film and an "O-scope" to read the actual track on the film and to get it aligned correctly. One can also use a new, unused trailer with a SR-D track on it as well for a loop. good luck-Monte  |  IP: Logged Demetris Thoupis Phenomenal Film Handler Posts: 1240 From: Aradippou, Larnaca, Cyprus Registered: Apr 2001 posted 09-10-2008 01:40 AM                     With the movement of the LED you will be able to achieve perhaps good ilumination. To see this without an osciloscope you need to set a dip switch on the CP650D (I think is dip switch 6 but I am not sure) to get the Cp650D to setup mode and scroll towards the video level seletion. From there when you move the LED for the digital reader you should see it moving from low volt to maximum 4.1v (if it is higher then you definately need a technician to come in to do alignment). It seems that the leds on these bracket move together but I may be wrong. To do a proper alignment of the soudheads you will need osciloscope and realtime analyzer or the CP650D software. Note that by fliping the Dip switch, should you change anything else you might lead yourself into trouble so if you are not fully aware of the procedure to properly aling a CP650D. I recon that most probably the LED level has faded and there should be a potentiometer adjustment somewhere on the projector to raise the LED level higher. The main issue that you need to achieve 4V of video level. If you have 4V and still have faulbacks to analogue then surely you will need a tech to come and do a proper alignment. Note that the Digital reader is the most complicated to aling unlike the analogue which in most cases its pretty straight forward. Whatever you do, DO NOT move the reader. Hopefully they are set ok from the factory or your technician. Demetris  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 09-10-2008 05:27 AM                     You CAN eyeball it in, but close enough really doesn't merit absolute accuracy....and SR-d is critical with error counts if not accurate. (......why you best need the 'scope' to eyeball that LED to get it dead center with the SR-D track with the film running....) There is a subsitute program that a lot of us tekkies have and that is WinDRAS 2.0 - a program installed in a laptop and with a serial cable attached to the processor and laptop to "see" what the camera eye is seeing on the film. This program works as a 2nd best to the actual testing above.  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 09-10-2008 08:57 AM                        Careful with that program. You are "looking" after delay and error correction. Louis  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 09-10-2008 09:07 AM                     I'm sorry to say this but stop...you are shooting blind without the proper tools and training. Nothing in the soundhead should be done stictly by eye or ear. You need both calibrated test films as well as the proper tools which include, WinDras, O-scope, test films and RTA. It really is that cut and dried. Anything you do by eye is likely to be as bad as it is good. Despite what Monte said, WinDras can be a very valuable tool but not for setting the LED position so much...it can be handy for items. If you know how to read the quick histogram, you can use that portion of Dras to set LED/lamp intensity. I'm not trying to discourage anyone from trying to improve things but the reality is that without the proper materials and training, I would think you have as much chance to make things worse as make them any better and you are not going to get it right, even if you do, by luck, improve things a little. Steve  |  IP: Logged Tim Reed Better Projection Pays Posts: 5246 From: Northampton, PA Registered: Sep 1999 posted 09-10-2008 10:20 AM                       Steve is absolutely right. This is not for the faint of heart (or inexperienced/untrained). It's quite a bit more involved than setting up A/V equipment.  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 09-10-2008 11:07 AM                        Whether it helps or not is almost totally dependent upon how badly it was aligned before you started! Louis  |  IP: Logged Randy Stankey Film God Posts: 6539 From: Erie, Pennsylvania Registered: Jun 99 posted 09-10-2008 11:11 AM                     I never thought DRAS was meant to align or set up a Dolby Digital system. Only to perform simple checkups on a system that has already been aligned using a scope, test film and an analyzer. In other words, DRAS would be used by a technician who receives reports of problems with a system. He can quickly hook up his laptop and get a readout on the system's performance without dragging out all his equipment. If he finds that there is a problem, he can fix it the right way but, if it's only a minor tweak or if he determines that the problem will keep until he has time to make a regular service call he will save himself a lot of work. I would never use DRAS to do a full alignment.  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 09-10-2008 12:45 PM                     Some also run DRAS parallel with the full testing, but true - never by itself to get absolute results. What I'm wondering also is with the Horizon having a basement reader: how's the wow and flutter with these machines?  |  IP: Logged Andrew Bangs Expert Film Handler Posts: 148 From: Kerrville, Texas, United States Registered: Sep 2008 posted 09-10-2008 10:57 PM                        First off thank you all. Frankly you have confirmed my own feelings and now I feel I have the facts to go to my superiors and ask for a tech to come out. I am an adventurous sort and have always learned by doing. but I have always had the Knowledge on just what I was qualified for or not as I could easily do more harm than good. this situation seems like it needs the definite touch of a professional. I think ore trouble began with poor Maintenance. Things became loose in the projector and with addition of unqualified hands jarring around the insides cleaning other components the problems were (no pun intended) Amplified. The other problem I have is that as Monty Eluded to with the digital gone the analog is now playing the audio and yes their is distinct flutter and I cannot get rid of it. I do realize I may get Booed and Hissed for this but does any one know if their is a sister program to WinDRAS 2.0 for the Mac... yes I said Mac... if so please let me know and also if the program has a price I will have to swing that by my boss. If their is no Mac Version I have a lead on a PC that I might be able to use. The thing that is most interesting to me is being able to look through the lens of the reader. I feel that if I could do that I might be better able to cut down on the flutter. Do you know of a way to get the lens feed from the Analog as well as the digital. Will this program do both? I only ask because the analog and digital on this machine is well out of tech spec and frankly right now we are loosing people to the background noise so something needs to be done immediately till a tech can make it out.  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 09-10-2008 11:24 PM                     There are some FT members who also have MACs instead of PC's, thus it could be possible that Dolby has a MAC version of DRAS - have to chek the Dolby site for that info. WinDRAS is only for the digital side of the audio spectrum. Optical is a whole different animal to align, yet more basic testing alignments techniques than with digital. Yet one has to do the optical alignments first before the digital alignments for a basement reader.  |  IP: Logged Joe Redifer You need a beating today Posts: 12859 From: Denver, Colorado Registered: May 99 posted 09-10-2008 11:32 PM                        No. Dolby hates Mac users. If you have a recent Mac laptop, however, it will have an Intel processor. Simply install Windows XP under "Boot Camp" and your laptop will be able to boot into Windows and run your DRAS. However you can bet that DRAS requires some bizarro, outdated PC-only connection from 1975 like a printer port or serial port to work... things that Macs don't have. Asking them to work with technology less than 10 years old like USB is simply asking way too much of Dolby! They'll support USB when it starts disappearing from computers. Hopefully I'm wrong and someone in the know can correct me, but I bet I'm right.  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 09-10-2008 11:38 PM                     Yea, the good ol' DB-9 thru serial connection. But, you can get USB to serial adapters (which I had to get for my recent laptop..) which works great. But, it's also handy to keep an old Pentium 266 laptop running Win98 floating around for the use of WinDRAS for then you definitely got serial ports to use.  |  IP: Logged Joe Redifer You need a beating today Posts: 12859 From: Denver, Colorado Registered: May 99 posted 09-10-2008 11:39 PM                        Did it work with DRAS?  |  IP: Logged

All times are Central (GMT -6:00)

This topic comprises 4 pages: 1  2  3  4

Printer-friendly view of this topic

Hop To: Select a Forum: Category: Operations -------------------- Digital Cinema Forum Film Handlers' Forum Large Format Forum Ground Level Feature Info, Trailer Attachments & REAL Credit Offsets Category: Community -------------------- Film-Yak Film Handlers' Movie Reviews The Afterlife Bob Maar's Joke-A-Thon Category: Classified -------------------- Equipment and Supplies Wanted/For Sale Help Wanted/Seeking Employment Category: System -------------------- Software Beta Testing Forum

The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion and agrees to release the authors from any and all liability.