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Author Topic: Sound problem with DTS film David Rigby Expert Film Handler Posts: 134 From: Chorlton, Manchester, UK Registered: May 2002 posted 06-16-2003 04:24 PM                     When I played a film with a DTS track the other night on my Vic 4 I found that there was an intermittent low pitched noise in the left channel - almost like white noise but less shrill. My assumption is that the Dolby cell is slightly out of alignment and so the left channel is picking up some of the timecode. is this correct or should I be looking elsewhere? The solar cell alignment was only done pretty coarsely when the cell was installed since I didn't have my CP50 working at the time. David  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 06-16-2003 04:40 PM                     Try gently pressing the film inward a hair while it is running and see if the noise goes away. Do you by any chance have a buzz track loop of film?  |  IP: Logged John Pytlak Film God Posts: 9987 From: Rochester, NY 14650-1922 Registered: Jan 2000 posted 06-16-2003 04:54 PM                        Assuming you were playing the analog track, I agree with Brad that you should check the lateral alignment. Sometimes the edge of the silver application is close to the edge of the scanned area, and could result in a noise like you describe. Accidently scanning the DTS track would be an irregular square-wave "putt-putt" or "motorboat" noise, and not a hissy "white noise".  |  IP: Logged Bruce Hansen Jedi Master Film Handler Posts: 847 From: Stone Mountain, GA, USA Registered: Dec 1999 posted 06-16-2003 05:10 PM                     If you run a film without DTS time code, do you still get the same noise?  |  IP: Logged David Rigby Expert Film Handler Posts: 134 From: Chorlton, Manchester, UK Registered: May 2002 posted 06-17-2003 03:56 AM                     The noise only appears on DTS film. I've never heard it on a plain old analogue track. Interestingly, it didn't happen on every reel of the DTS print, but on about 5 of 7 - and sometimes it vanishes for extended periods (say 10 minutes) in a reel. I'll try the nudging trick to see if it goes away. The fact that the noise was only in the left channel is what made me think it's the DTS track. (NB I'm currently only using the preamp output on my CP50, so only 2 channels). John - the description as 'white noise' was probably not a good one on my part : it's fairly low pitched but has a similar 'random' quality to white noise. Perhaps it could be described as a 'motor boat' noise. Not sure if I have a buzz track - I may well have a loop sitting around somewhere; I'll take a look. Thanks guys David  |  IP: Logged Michael Schaffer "Where is the Boardwalk Hotel?" Posts: 4143 From: Boston, MA Registered: Apr 2002 posted 06-17-2003 04:12 AM                        It happens from time to time. I remember the German prints of "Titanic" had misprinted timecode on some reels. So some smaller second-run theatres with analog only couldn`t play the film without severe sound problems.  |  IP: Logged David Rigby Expert Film Handler Posts: 134 From: Chorlton, Manchester, UK Registered: May 2002 posted 06-17-2003 07:34 AM                     Hmm. I did wonder whether it might be a printing problem since the background noise isn't there 100% of the time. I'd prefer a cell misalignment since that's just a bit of fiddling. I'll post here with what I find over the weekend (probably won't get time to sort this before then). For future reference, how common are timecode printing problems? Thanks as always folks David  |  IP: Logged Mitchell Dvoskin Phenomenal Film Handler Posts: 1869 From: West Milford, NJ, USA Registered: Jan 2001 posted 06-17-2003 07:40 AM                     The only way you are going to know is with an official buzz track loop. Adjusting by ear with release prints will drive you crazy, since many of them are printed slightly out of spec.  |  IP: Logged John Pytlak Film God Posts: 9987 From: Rochester, NY 14650-1922 Registered: Jan 2000 posted 06-17-2003 08:10 AM                        SMPTE Recommended Practice RP115 specifies the position of the Photographic Control and Data Record on 35mm prints. The centerline should be 0.297 inches (7.54mm) from the reference edge of the print. The inner edge of the analog audio record should be 0.281 inches (7.14mm) from the reference edge.  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 06-18-2003 09:18 PM                     remeber that the cinemecanica slits have a width adjustment so once the lens assembly is correctly centred its width is adjusted to limit its scanning width to between the two tones of the smpte buzz track  |  IP: Logged Rick Long Jedi Master Film Handler Posts: 759 From: Toronto, Ontario, Canada Registered: Nov 1999 posted 06-18-2003 11:44 PM                     Perhaps the best description of DTS being picked up in the optical scanner is "kinda sounds like a vaccum cleaner".  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 06-19-2003 09:02 AM                     "Perhaps the best description of DTS being picked up in the optical scanner is "kinda sounds like a vaccum cleaner"." _________________________________________________________________ On a system with good subwoofers it also can sound like a A Pratt And Whitney radial airplane engine...... The only thing you're missing is the 100 mph hurricane force winds that are also being generated by the propeller.....  |  IP: Logged Randy Stankey Film God Posts: 6539 From: Erie, Pennsylvania Registered: Jun 99 posted 06-19-2003 10:30 AM                     When I had reports of alignment problems that caused the DTS track to be read in the analog reader I would ask the person if it sounded like a computer modem.  |  IP: Logged Larry Zuverink Film Handler Posts: 98 From: Caledonia, MI, USA Registered: Nov 2002 posted 06-19-2003 01:44 PM                     V4's as well as V9's are known for having very week cells. Any little thing can knock them out of alignment. Even worse with the Kelmar cell. So even if it had been aligned at first it could be a mile and a half off now. Your best bet is a full A-chain.  |  IP: Logged Karen Hultgren Master Film Handler Posts: 492 From: Agoura Hills, CA, USA Registered: Mar 2000 posted 06-19-2003 04:58 PM                        Use a buzz track loop and realign your solar cell - it's picking up the DTS track. Karen at DTS khultgren@dtsonline.com  |  IP: Logged

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