This is topic 4 Track Mag sound in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by Travis Cape (Member # 466) on 07-07-2000, 12:16 AM:
We are in the process of installing a CP500 in our theatre with the 701 penthouse. Being the curious little projectionist that I am, I want to install 4 track on Projector 2. Yes, I know prints are tough, but out there. I bought the 685 card, got a CP200 mag preamp, and a power supply. I was wondering which penthouse I should use. If the heads are good, which is better? I have access to Simplex and RCA. I have XL's with RCA 9050's so either should be correct. I just want to hear it talk to say that I did.
Posted by Josh Jones (Member # 447) on 07-07-2000, 12:51 AM:
sounds like me. I messed with a RCA9010 once
never got it to talk thoughJosh
Posted by John Walsh (Member # 168) on 07-07-2000, 10:04 AM:
They both are probably OK, I would choose whichever mounts the easiest. Verify that the sprockets on the rest of the projector are the "Fox" type. In the early 1980's Teccon made mag heads that were a big improvement over earlier heads; you might want to look around for one of those. Since no one really uses 4-track anymore, you might find one cheap.
Posted by Gordon McLeod (Member # 33) on 07-08-2000, 11:55 AM:
Mounting can also introduce a sync problem if you don't have the correct spacer plate adapter
Posted by Travis Cape (Member # 466) on 07-08-2000, 11:13 PM:
I think I should go with the Simplex penthouses. Do they just need to mount directly to the head with the four screws? By the way, I do have the "Fox" sprockets. This is just another one of my ways to make a boring single screen job interesting for me. I have all of the test film for 4-track, now to find some prints.
Posted by John Wilson (Member # 269) on 07-09-2000, 01:47 AM:
>>I have all of the test film for 4-track, now to find some prints.<<...which may prove difficult. We've got (although I'm not sure it still exists) a near mint 35mm print of The Blues Brothers in four track available to us here but there's not a lot of money left in that one anymore.
You may get some from collectors, but...
I ran a mag/opt print of Empire Strikes Back in 1983. The reel lengths were still the same as an optical print, but anyone remembering that title will recall it was 119 minutes long on six reels (nothing today, but in those days, those made for some pretty big reels of film). Now add to those already full reels a mag track and each 2000 went over the rim by about 1/2 an inch!
Fun, fun, fun...
Posted by John Pytlak (Member # 331) on 07-10-2000, 06:35 AM:
Unless stored properly, magnetic tracks on triacetate prints made them more prone to "vinegar syndrome". Iron (rusted cans or reels, magnetic stripe) serves as a catalyst for the hydrolysis reaction. The binders used for magnetic tracks were also prone to hydrolysis.If you have striped prints that are still in good condition, you should continue to store them in cool and dry conditions. Unsealed containers allow venting of the acid by-products, so the acid won't build up. If sealed containers are used, Molecular Sieves will adsorb both moisture and acid, retarding "vinegar syndrome". See SMPTE Recommended Practice RP131 "Storage of Motion Picture Films" or Kodak's publication H-23 "The Book of Film Care":
http://www.kodak.com/US/en/motion/support/technical/care.shtml
------------------
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
Posted by David Kilderry (Member # 142) on 07-11-2000, 04:04 AM:
AAAAHHHHHH good old 4-track. Last ones seen down this way were "Blues Brothers", "Xanadu" and a re-run of "Lawrance Of Arabia".Oh, and the fantastic scope 4-track ad for Marlborough. I remember the other shift one day switching to mag for this ad only to have no sound - they forgot to thread the mag penthouse!
By early 1980's here all magnetic was 70mm. If you really want to smell what true vinegar syndrome smells and looks like, you check out my 70mm spools of "Mad, Mad, Mad, Mad World" it is faded, shrunken and stinks to high you know where!
David
Posted by David Johnson (Member # 173) on 07-11-2000, 07:09 AM:
David, Did you know last week Northland ran a 4 track print of "West Side Story" so there are still a few around.
David
Posted by Rick Long (Member # 213) on 07-11-2000, 04:04 PM:
In the last couple of dozen years, the only 4-track prints that I have run are:
The Song Remains The Same - Led Zepplin
The Buddy Holly Story
The Slipper and the Rose
Earthquake (4th track used to trigger the Sensurround equipment)
The Rose Many 35MM mag prints had a 12 kHz tone to switch in the surround track (better described as an "effects" track) whenever surround effects were desired. Unlike Dolby stereo recordings, this track was only used to enhance dramatic screen action. (the bells of the abbey in Sound of Music, a roll of thunder in King of Kings, ect.). If your M.P.U. does not have a 12 kHz filter, you may hear (actually more feel, than hear) an annoying high-frequency whistle from the surrounds. You may end up spending a lot of time with high-Q (notch) filters trying to get around this problem. It all depends on the print.
Good luck!
Posted by John Wilson (Member # 269) on 07-14-2000, 04:32 AM:
David,I remember running Marlboro 'Early Morn' at the Westline... (sob) It sure looked great on that screen. Ours wasn't 4 track though. I didn't even know a four track of this existed until a friend of mine dragged it out at his home cinema once. 
there's a four track of Xanadu around? Hmmmmmmm...