Film-Tech Forum ARCHIVE: Interface Issues

This is topic Interface Issues in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Peter Egglington (Member # 3448) on 11-07-2005, 03:31 PM:

Hello

I am new to this site and need some assistance.

I have to install a CP650 with DTS, a Sony DFP2000 and a CP200 to allow all the various mag formats to be played. My customer wants to use an internal crossover in the CP650 for the stage channels. How could I do this? I am led to believe that the Sony has to 'hang' on the the end of the chain and thus an internal crossover in the CP650 will not work.

I am new to this business, so all comments are welcome on how I should do this, including how the system should revert in the event of any digital system failing would be nice.

Also, this is a 2 projector installation. How should the changeover system be wired?

Peter

Posted by Ben Wales (Member # 92) on 11-07-2005, 04:08 PM:

Peter:

Are you able to give more details on your installation, ie would it be 35mm and 70mm Mag Sound Formats?.

It would not be advisable to use two different Dolby Processors for this installation as the CP650 would be more suitable for the various Digtal Inputs like DTS and SDDS etc.

As for the mag formats, a Dolby MPU-1 or later version is required and the CP650 has 6 Channel imput.

I would advise that a Dolby Trained Engineer is contracted to set and Align this equipment up, if you are uncertain about this installation as it will require specialist equipment for proper set up.

As far I am aware, there is no Internal x-over Speaker network on a CP650, The latest QSC range of Amps do have built-in X-over Hf/Lf outputs.

Posted by Steve Guttag (Member # 268) on 11-07-2005, 04:52 PM:

The number of ways of accomplishing this are many.

The question is, why the CP200 and CP650...all that the CP650 brings to this installation is Dolby Digital and possibly some AC-3 stuff or the crossovers.

Yes, the CP650XO has the ability to have up to 3-way crossovers (with only 3-screen channels).

Are these items in possession for the project or do they need to be aquired?

With the CP200, you have the infamous JM11/JM21 loop that has every channel except subwoofer in it. You could have the SDDS in that loop with the DTS or you could take the plan of let the CP200 feed the SDDS, the SDDS feed the DTS interface board and then let that feed the CP650 6-channel input.

Note, if you have LC and RC (aka Le and Re) stage channels, it really begs the question of why the CP650 since it can not handle those channels with the internal crossover (if memory serves, they are only active with the Cat 778 on the CP650 which means digital outputs only in AES3 form.

Yet another option is to explore using the Panstereo CSP4600 to augment the CP650...however I would check to see if firmware has been updated to work with the CP650 and to have the CSP4600 to follow the CP650s changeover. Note, with the Panastereo CSP4600, the CP200 becomes unecessay since it has the ability to handle two projectors of 35 and 70mm magnetic and adds the LC and RC channels.

Posted by Mark Gulbrandsen (Member # 72) on 11-07-2005, 04:58 PM:

I would also push for the 4600. Serving as the heart of the system not only would it be the best sounding piece in the chain it would also make interfacing all the outboard digital units alot easier. The CSP'S mag input can also be very easily configured to accept a digital input.

Steve, Assuming that they used the 4600 I wonder what the fallback time would be for the Sony..... My experience has been that they are somewhat slow at going back and forth between analog and digital as compared to the DTS or DA-20,especiallly bad hooked on a CP-500. I would be tempted in this case to just use the Sony the same way I would be hooking in the DTS processor... just by using the Sony's output....hope they get good prints!

Mark

Posted by Ben Wales (Member # 92) on 11-07-2005, 05:35 PM:

There are two Panstereo installed I am have seen, one at the NFT (Theatre One) in London and recently at the Rex Cinema Berkampstead.

I had thought about this option after I posted my earlier posting on this subject.

Both of the above Cinemas have two projectors on change over's and 70mm mag sound and both places are happy with the Panstereo system.

Posted by Brad Miller (Member # 2) on 11-07-2005, 09:56 PM:

Peter, we really need to know specifically what mag formats are desired to be played here. You may very well be fine with the CP650 only, or you may want to dump the CP650 out of the equation.

As far as the Sony goes, I have always achieved a better end result by custom making interface cables and routing it into the JM11/JM21 circuit on the CP200 or into format 11 on the CP650.

I haven't used the Panastereo yet, but depending on your answer to the above question, you may want to go that route.

Posted by Peter Egglington (Member # 3448) on 11-08-2005, 01:25 AM:

Hi Everybody.

Many thanks for your replies. This setup is in a private collectors house. The owner wants to use the CP200 to decode all mag formats (35mm 4 track, and all 70mm formats up to format 43). However, he wants to use a CP650 for all other applications (analog 35mm) to take use of the superior signal processing, and for injecting audio from D5 players and DVD players into the system.

Aside from the CP650, which he has purchased, all the equipment is there and hooked up through the CP200.

Any further advances?

Peter

Posted by Ben Wales (Member # 92) on 11-08-2005, 03:50 PM:

Sounds that this Private Collector Cinema Owner has money to burn.

Peter: what make of Projectors is he installing and is it in the UK?.

Posted by Steve Guttag (Member # 268) on 11-08-2005, 05:02 PM:

Peter, by your description, the CP650 seems superfelous. The CP200, with current Cat 108C, Cat 517s and Cat 560s, and Cat 150F will do just fine with all of the decoding and not go though extra A/D - D/A conversions.

Rather than blow the money on a CP650XO, why not add a Dolby DMA-8 to provide the digital audio pathway? With the DMA-8 you will have some 4 or 5 different digital pathways in of which one of the inputs is an 8-channel AES input, there are two S/PDIF inputs...one optical, one coaxal... and an AES3-id input. There is an option board for SDI sources to strip AES audio embedded on the SDI signal.

Certainly more flexible than the CP650.

Again, does your screening room have 5-screen channels?

Posted by Peter Egglington (Member # 3448) on 11-09-2005, 02:09 AM:

The collector already has a pair of Victoria 10's and lives in Lerwick.

Posted by Brad Miller (Member # 2) on 11-09-2005, 02:33 AM:

Peter, when you come onto these forums and ask for help, it is customary to answer the questions put forth so people are able to help you. We aren't mind readers.

quote: Steve Guttag
Again, does your screening room have 5-screen channels?

Steve asked that for a reason. It's a very legitimate question.

Posted by Mark Gulbrandsen (Member # 72) on 11-09-2005, 07:41 AM:

quote:
However, he wants to use a CP650 for all other applications (analog 35mm) to take use of the superior signal processing,

Ha! Then he ought to do an A-B comoparison of the 650 vs. the Panastereo. The Pana easily wins hands down!

Brad,
Making your own interface caables has nothing to do with the slow switching time of the Sony.

Mark

Posted by David Graham Rose (Member # 1450) on 11-09-2005, 11:08 AM:

G

Posted by Peter Egglington (Member # 3448) on 11-09-2005, 01:16 PM:

Hello

My apologies for not responding to all the questions asked - I'm a bit green with all this!

To answer the question, yes the theatre does have 5 stage channels and is currently wired to support conventional Todd-AO and format 43 (and all intervening formats as well).

Peter

Posted by Brad Miller (Member # 2) on 11-09-2005, 02:09 PM:

Mark, down here we don't have dropout problems like Utah does, so it's really a non-issue. [Razz]

Peter, the CP200 with a DA20 will be your easiest route between the two Dolby options.

Posted by Ben Wales (Member # 92) on 11-09-2005, 03:51 PM:

Interesting the Private Cinema owner has a pair of Victoria 10's, most of them are accounted in the UK.

The only ones I have that are not in use is a pair in storage in London and one (partly) in Manachester and one display one may still be at Dundee.

I would go along with Steve's suggestions and upgrade the CP200 with the Dolby Interface Dolby cards for the Digital imputs.

Posted by Louis Bornwasser (Member # 3063) on 11-09-2005, 07:16 PM:

FYI the DA-20 is going away soon. Louis

Posted by Peter Egglington (Member # 3448) on 11-10-2005, 01:31 AM:

Hello Louis

Does this mean that Dolby will cease to support the DA20?

Peter

Posted by Mark Gulbrandsen (Member # 72) on 11-11-2005, 02:41 AM:

quote: Brad Miller
Mark, down here we don't have dropout problems like Utah does, so it's really a non-issue.

Brad, I don't seem to remember mentioning dropouts ala Sony, not in eons. Actually all of the Sony players around here work amazingly well, what I was talking about is the inherently slow switching of the 2000 unit when it does default.... like when there is no SDDS on the film, or if the track is bad.....

quote: Brad Miller
Peter, the CP200 with a DA20 will be your easiest route between the two Dolby options.

Again, I don't agree and until you've used the Panastereo which has up to three digital inputs that are not based on the limiting single JM loop through of the 200 there is no basis for this statement. For playing back from multiple digital sources as this fellow is going to do its impossible to beat the CSP'sconvenience.

Mark