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Author Topic: Over driven preamps? Greg Mueller Phenomenal Film Handler Posts: 1687 From: Port Gamble, WA Registered: Jun 99 posted 08-13-2000 11:47 AM                        I need advice. I'm running a stock DP70 into a CP65. There's a place in The Matrix where the music comes way up (where Mr Reeves is waking up and sees the rest of reality) and either the sound track is distorted (optical) or the preamps are crashing. How can I tell which? What do I do about it? ------------------ Greg Mueller Amateur Astronomer, Machinist, Filmnut  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 08-13-2000 03:36 PM                     Greg, Take a look at that section of the films soundtrack and see if the sound track is "Hardwalled" against the sides of the track indicating over modulation. This would be definate evedence that the level was not carefully controled during recording. There is a definate 100% maximum level in optical recording and no more. At 101% it will "Hardwall" and cause distortion. If the track looks fine for that section of the film put a scope on the preamp output and watch for it to hard clip on the extreme peaks. Unless you have your calibration level set way too high chances of a preamp causing this are slim. The more likely is the film itself. Mark P.S. Didn't we communicate on astronomy related issues a few years back???  |  IP: Logged John Pytlak Film God Posts: 9987 From: Rochester, NY 14650-1922 Registered: Jan 2000 posted 08-14-2000 08:31 AM                        Mark makes a good point about how easy it is to physically see overmodulation on an analog track by simply looking at it. If the track is overmodulated and "clipping the peaks", it will have noticable distortion. Digital sound provides more "headroom", but also has limits. But you can't simply look at the bits and tell, as you can with an analog optical track. ------------------ John P. Pytlak, Senior Technical Specialist Worldwide Technical Services, Entertainment Imaging Eastman Kodak Company Research Labs, Building 69, Room 7419 Rochester, New York, 14650-1922 USA Tel: 716-477-5325 Fax: 716-722-7243 E-Mail: john.pytlak@kodak.com  |  IP: Logged Stefan Scholz Expert Film Handler Posts: 223 From: Schoenberg, Germany Registered: Sep 1999 posted 08-14-2000 11:24 AM                        I have feeling, that with all the digital formats going on, the analogue sound is not printmastered at all. It is basicly a 4:2 folddown with some above threshold compression of the original 5.1 digital, and even stored on the same Magneto-optical disc. Especially in comparison to some 1989/ 92 SR mixes the modern analoge simply sucks.  |  IP: Logged Scott Morrison Film Handler Posts: 9 From: Los Angeles, CA, USA Registered: Sep 1999 posted 08-14-2000 01:56 PM                        Your comment about the analog not being printmastered is not true. Especially on a film like "The Matrix" The mixers on the dub-stage for that film were very careful about the 2 track mix and associated printmastering. The same crew also did "The Perfect Storm" with equal care. If it were up to Dolby, we would always spend the proper time to printmaster the 2 track, however clients budgets may only allow for what they deem to be necessary. Just like everything else its a 'money' thing.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 08-15-2000 05:31 AM                     At Todd-AO an actual release print is run and compared to the 2 track master for approval. This was the reason that the the new slits were developed for the DP-70 optical sound head as thats what they use at Todd to run on. The older slits were not adaquate on the high end response for this purpose so the new photographically produced slits were made up. I don't know if every mix studio does this or not, and again it may depend on how much $$ is available in the budget, but it's obvious that the people at Todd are doing some good quality control here on the work they put out. Mark  |  IP: Logged

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