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

» Film-Tech Forum ARCHIVE   » Operations   » Digital Cinema Forum   » Problem Using DTS 6AD External 6ch Input (Page 1)

This topic comprises 2 pages: 1  2

Author Topic: Problem Using DTS 6AD External 6ch Input Jeremy Weigel Phenomenal Film Handler Posts: 1062 From: Edmond, OK, USA Registered: Mar 2007 posted 05-09-2009 12:09 AM                     We recently converted 2 screens to digital (Real D). We are using GDC servers and running the audio first through a USL DAX-602 D/A converter then into the DTS 6AD 6CH External input on one of the machines and a CP500 on the other. The problem I have is that the left channel sounds noticeably louder than the center and right on playback with the 6AD. I've checked the SPL using the internal pink noise generator of the 6AD and all levels and EQing are checking out spot on. I have also run the Empirical Test disc and it checks out. For the time being I have lowered the SPL of the left channel so that playback sounds "balanced" to compensate for now. Unfortunately there are no audio test files such as pink noise on the GDC. Has anyone else encountered a similar problem?  |  IP: Logged Demetris Thoupis Phenomenal Film Handler Posts: 1240 From: Aradippou, Larnaca, Cyprus Registered: Apr 2001 posted 05-09-2009 12:33 AM                     The USL DAX-602 D/A has a fixed output at 300mVrms reference level BUT it is adjustable via a computer software. I am sure Clint can inform you more. Is there a chance by some "cough cough trimming cough cough" someone messed it up? Demetris  |  IP: Logged Jeremy Weigel Phenomenal Film Handler Posts: 1062 From: Edmond, OK, USA Registered: Mar 2007 posted 05-09-2009 12:58 AM                     I think I pretty much ruled out the D/A converter since I swapped it with the other one that's connected to the CP500 and the issue remained.  |  IP: Logged Demetris Thoupis Phenomenal Film Handler Posts: 1240 From: Aradippou, Larnaca, Cyprus Registered: Apr 2001 posted 05-09-2009 02:20 AM                     Well as I said before, there is a software to trim the audio output from the USL unit to trim the left channel down should you wish too. Demetris  |  IP: Logged David Zylstra Master Film Handler Posts: 432 From: Novi, MI, USA Registered: Mar 2007 posted 05-09-2009 11:25 AM                     I found that we had almost this exact same problem with the DoReMi analog output plugged into our 6AD inputs. I would suspect your connecting cable is wired wrong - the DTS 6AD uses specific pins for the low (-) side of each channel's signal with only 1 ground pin but the Dolby has unbalanced input and ties all unused pins to ground (manuals for both units are in the "Manuals" section - take a look at the differences in input pinout). It took our service provider/installer 6 months to find and ship the right cables (they shipped the wrong ones twice) - I ended up modifying their original cables with the correct pinouts myself to prove what the issue was.  |  IP: Logged Pete Naples Phenomenal Film Handler Posts: 1565 From: Dunfermline, Scotland Registered: Feb 2001 posted 05-09-2009 12:11 PM                     quote: David Zylstra It took our service provider/installer 6 months to find and ship the right cables Does no one own a soldering iron anymore?!  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 05-09-2009 03:31 PM                        Not in America (except us!) LOuis  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 05-09-2009 05:26 PM                     See...there you go...thats the problem...soldering the Dsub instead of crimping. I know for many of the "alternative content" companies we deal with...we tell them to just skip the cables...we'll take care of that...way too many bad cables. Same goes for the DCinema cable companies. I don't know if they still do, but DoReMi was using analog audio cables instead of AES audio cables (difference impedence). Dolby tells me we are the only ones that make our own Dolby Digital Reader cables...I find that strange and sad, if true. They are not that hard and one then only uses as long a cable as needed and it can be dressed properly in conduit/greenfield/liquidtight. Steve  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 05-09-2009 07:56 PM                     quote: Louis Bornwasser Not in America (except us!) LOuis Ha! I even own(personally)Surface Mount de-soldering/soldering gear! DAX works via NETBIOS so if you have that configured on your laptop all you should have to do is type "DAX" in your web browser and the setup program will come up via the ethernet port. There is an alternative IP address(try 169.254.1.123 according to the manual) use with a cross over cable but DAX works on my laptop. We manufacture all of our own cables too and I agree with Steve.... probably an improperly made up cable. I don't agree that its bad to solder cables though, For years I've used a special silver alloy solder on my cables and I'd claim its actually better than crimps. You won't fnid a single crimped connection in any of the Space Shuttle hardware!! It just takes an experienced tech to do it right. It pays to hire a good service organization to install stuff like this... Not the Wrong Company! Mark  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 05-09-2009 09:59 PM                     Solder has its place and I do a lot of it. On DSubs...I find crimps to be superior. They are faster and generally will do a better job of conducting. Steve  |  IP: Logged Jeremy Weigel Phenomenal Film Handler Posts: 1062 From: Edmond, OK, USA Registered: Mar 2007 posted 05-10-2009 01:16 AM                     Thanks for the input guys. I'll make up a new cable between the DAX and 6AD to replace the one that the install team used as well as hook up a laptop to the DAX. The company that installed the equipment has been told by GDC that they (GDC) are working on creating the audio test files.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 05-10-2009 01:53 PM                     quote: Steve Guttag I find crimps to be superior I guess if NASA also found them superior they'd be using them too! Any MXF file should play back just fine on the GDC. No need to wait for them.... Where is SMPTE during all this. They SHOULD be supplying both aural and vuisual test files for D-Cinema. Mark  |  IP: Logged Julio Roberto Jedi Master Film Handler Posts: 938 From: Madrid, Madrid, Spain Registered: Oct 2008 posted 05-10-2009 03:17 PM                    Perhaps this could be of help. It's not designed for what we want here exactly, but may be of some use to some for similar purposes. http://www.dcimovies.com/reference/ [link is to page from DCI on how to order their DCI reference package in a disc and how to obtain a KDM for playback of the cyphered part on your server]  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 05-10-2009 04:09 PM                     Test material should not require a key but a one time purchase of the material and it should be available from SMPTE like other test material  |  IP: Logged Julio Roberto Jedi Master Film Handler Posts: 938 From: Madrid, Madrid, Spain Registered: Oct 2008 posted 05-10-2009 06:15 PM                    I believe the test material includes both, unencrypted and encrypted content. The encrypted content is to test the (working) decryption on your server. The key delivery message is generated on-line, so you can have easy access to it when you want for any server. I believe it doesn't expire once you have it. If you don't have access to any other test material and don't know how to create your own, it could be a sensible route to go. As I said, it's neither perfect nor designed for what we are talking about here, but it could be useful under similar circunstances. For only $18 for a disc, I say it's worth it for a lot of us to have around. At least we know the content itself is carefuly made to specs (which our equipment may not follow, but nonetheless).  |  IP: Logged

All times are Central (GMT -6:00)

This topic comprises 2 pages: 1  2

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.