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Author Topic: CP-500 & 4-Track Mag Don Furr Jedi Master Film Handler Posts: 509 From: Sun City, Ca USA Registered: Nov 2002 posted 04-25-2009 12:56 PM                     I've looked at the operating manual and can't find anything about 35mm 4 track mag. I see the instructions about 70mm 6 track. Will there be a problem running 35mm 4 track with a CP500? Thanks for your help. Don  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 04-25-2009 01:40 PM                     Sure it'll work but you'll have to do the surround switching/filtering in the MPU for sure. Just run the MPU outputs into the L,C,R,S inputs(DB connector) of the 500 and build a special format to rurn off the NR(if necessary). Just like feeding in a DTS or DA-20. I don't know if it's actually worth the effort to be honest... I owned alot of 1950's/60's 35mm MAG prints including one of "Music Man" over the years and none of them were the least bit impressive. Not till the very end of 35mm mag(wasn't it one of the Barbera Streisand's movies) was the sound at all decent. I have a brand new Teccon 4 track head for a reasonable price if anyone is interested in it. I believe it was for a JJ but it could be adapted pretty easily to other machines. Mark  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 04-25-2009 02:04 PM                     The CP500 has several 4-track mag canned formats. I'm pretty sure format 23 (NR) is one of them...IF you have a CP500/70 in order to get the 4 channels of "A-type" noise reduction. Mark is right, any surround switching will need to be done by the MPU or other filtering. Note too, the CP500 is looking for 388mV from its "Mag Input" like the CP65...stupid as the 300mV standard was already there. As to the sound of 35mm 4-track...I've seen a great many set up poorly...well done it is quite impressive as compared to its mono-optical counterpart. With NR, it is definitely superior to anything SVA ever had. Most people don't realize how much better 16mm Mag is over 16mm optical...it is pretty night and day there too. Generally, what I find with many that try to play 4-track in modern theatres with X-curve EQs are very over-bright sounding tracks. If you apply suitable filtering to impose the academy curve onto the output of the preamps, before hitting the cinema processor (and presumming not using NR, of course)...you have a very pleasing sounding track that, despite the roll-offs imposed by the aforementioned filters, will be full of highs and lows. Steve  |  IP: Logged Don Furr Jedi Master Film Handler Posts: 509 From: Sun City, Ca USA Registered: Nov 2002 posted 04-25-2009 02:28 PM                     Thanks Mark and Steve for your help. I'm using the Dolby MPU-1 (with the surround switching card) now so I assume it will work equally well with the CP-500.  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 04-25-2009 03:48 PM                     Yep...it will work...particularly if you have the Cat 92Cs to get the gain. Note, the Cat 93 was a so-so switch card...while it did the switching just fine...it doesn't really kill the 12KHz tone...just knocks it down a peg. That tone should really be nailed with a notch filter (and I mean like 60dB or more) and on top of that, put a LPF at around 8KHz...at least 2nd order...it will knock down the hiss and the tone a bit more. With those filters...one almost never needs to switch the track on/off anymore! Steve  |  IP: Logged Don Furr Jedi Master Film Handler Posts: 509 From: Sun City, Ca USA Registered: Nov 2002 posted 04-25-2009 04:14 PM                     Thanks Steve...that's good to know.  |  IP: Logged John Walsh Film God Posts: 2490 From: Connecticut, USA, Earth, Milky Way Registered: Oct 1999 posted 04-25-2009 05:44 PM                     Off topic, but ... how bad really was the mag surround track on 35mm? It doesn't seem that much bigger than the screen channels. Or was the idea that the screen channels would generally have something going on all the time to bury any noise, while the surrounds would have extended periods of no audio?  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 04-25-2009 05:59 PM                     Early stuff is not much better than AM radio John... Because of the X curve and thats about all those early heads(and RCA speakers)could do. It's possible with a Teccon head and a nice Dolby or Teccon head end system that response with pink noise and so on to go out to 10 to 12 khz consistantly. Mark  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 04-25-2009 06:42 PM                     Actually, the response from 4-track from a modern system can easily go out to 16KHz...I've set up enough recently to know. For early systems...it is actually much better than Mark states. The prints were mixed to the theatres of the day since they didn't have much in the way of "sound warping" circuits. As such, when they are played back on modern systems...they are very strident. They also sound thin on a modern system. However, when played back on a system of the era in a theatre of the era, they actually are dramatically better than optical sound. There is a lot of pre-emphasis clearly put into the mixes and due to the boominess of the theatres of that era...not as much bass. Seriously...if you put an academy filter on one of those tracks before you play it back in a modern theatre...they are really quite good. They don't have the bass of a modern track, for sure but dialog is every bit as easy to understand (maybe more so with the way folks mix today) and they panned the dialog around back then...which for me is a superior method than mere mono dialog...very distracting. Steve  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 04-25-2009 08:49 PM                        You will find not much above 7k on older prints without nr. I concur that 16-20k was possible. Unfortunately there was not much hf on mag better than optical. (5db down at 5k for optical; 7db down at 7k for magnetic) It was thought that hf was "bad" and so was just not mixed. I "wide banded" an old Ampex system for "Ryan's Daughter." The film sounded exactly the same, but the hiss was high fidelity. Louis  |  IP: Logged Tony Bandiera Jr Film God Posts: 3067 From: Moreland Idaho Registered: Apr 2004 posted 04-26-2009 12:52 AM                     quote: Mark Gulbrandsen Not till the very end of 35mm mag(wasn't it one of the Barbera Streisand's movies) The film was "Yentyl" (not sure I spelled that right) I had to do a few mag tune-ups when I was with RCA Service for that film. quote: Mark Gulbrandsen I have a brand new Teccon 4 track head for a reasonable price if anyone is interested in it. Mark, you got any 6-track 70mm for Simplex or Century available? Shoot me a PM or phone call if you do.  |  IP: Logged Michael Schaffer "Where is the Boardwalk Hotel?" Posts: 4143 From: Boston, MA Registered: Apr 2002 posted 04-26-2009 12:57 AM                        So Mark G. turns out to be a closet Streisand fan. Somehow, I am not surprised...but did we really have to find out in this way?  |  IP: Logged Sam D. Chavez Film God Posts: 2153 From: Martinez, CA USA Registered: Aug 2003 posted 04-26-2009 02:49 AM                       Spot on Michael! I was just thinking the same thing as I was listening to Ella/Louis Armstrong "Autumn in New York" recording looking at my tulips.  |  IP: Logged Demetris Thoupis Phenomenal Film Handler Posts: 1240 From: Aradippou, Larnaca, Cyprus Registered: Apr 2001 posted 04-26-2009 04:45 AM                     Sam I didn't know you were a flower man!  |  IP: Logged Sam D. Chavez Film God Posts: 2153 From: Martinez, CA USA Registered: Aug 2003 posted 04-26-2009 10:49 AM                       It was too good to pass up.  |  IP: Logged

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