Film-Tech Forum ARCHIVE: 70 mm with CP650

This is topic 70 mm with CP650 in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Luca Rossi (Member # 8691) on 02-24-2015, 10:18 PM:

Dear All,
i use normally 70mm analog audio format 42,43 and six track SR with CP500/70 set. Now we have to built two new 70mm installation obviously with CP 650 with cat 790 inside, on my old literature i have anything about use of 650 with 70 mm format, someone have experience about this?

Posted by Leo Enticknap (Member # 534) on 02-25-2015, 08:07 PM:

At one of our two theaters we kept our CP200 after the 650 was installed, and now use it only for 70mm mag. The power amps are in a rack behind the screen and the audio goes from the booth to them using a QSC digital transmitter/receiver at either end, and cat6 cable going across the ceiling. The input to that transmitter can be swapped between the 200 and the 650 as needed, using a patch bay.

You could take the output from a mag preamp unit (e.g. a standalone MPU-1) into a 650 using the analog multi-channel input if you need to, but doing that may be complicated by (a) the need to get the output from a DTS player into your 650 as well, if you intend to play DTS 70, and/or (b) issues around supporting both 5.1 70mm and "special venue" (five stage channels plus mono surround) at the touch of a button.

We found that using an entirely separate processor exclusively for mag and a patch bay to switch between processors was the easiest way to achieve a booth installation that uses a CP650 as the main processor but also supports all the DTS and mag 70mm audio formats.

Posted by Steve Guttag (Member # 268) on 02-26-2015, 06:00 AM:

Leo...what is it that the CP650 brings to the table? The CP200 can do it all.

Posted by Marcel Birgelen (Member # 6801) on 02-26-2015, 08:46 AM:

One sound processor to rule them all! Steve will even fly a rocketship with it if he has to [Wink]

I guess the CP650 isn't really a wrong choice as main processor if you're primarily playing SRD 35mm and DCI content.

Posted by Leo Enticknap (Member # 534) on 02-26-2015, 09:40 AM:

quote: Steve Guttag
Leo...what is it that the CP650 brings to the table? The CP200 can do it all.

I don't know what the rationale was behind configuring that booth that way, because it was done before I was hired. No AES input for the digital cinema server on the 200, maybe? Maybe when Dolby digital (35mm) was put in, installing the CP650 was a cheaper and/or easier option than adding a DA20 to the CP200 rig. But that's speculation - I don't know.

If I were starting from a blank piece of paper, I'd do what has been done at our other place, which is to have a CP200/MPU1 combo for all the film sound, and an AP20 for all the non-film digital audio sources, with the EQ-ed output of the CP200 going into the AP20 on a "flat" preset. This enables us to keep the unsurpassed performance of the CP200 for stereo variable area film soundtracks and a signal path that is digital as far as possible for DCPs, optical discs and laptop-thru-HDMI audio for the odd special show.

But one rarely gets to start with a blank piece of paper, and our CP650/CP200/patch bay arrangement in this house works reasonably well as a way of getting round the restricted number of multi-channel analog inputs and the lack of a mag preamp that can be a significant restriction when using a 650 as the main processor in an arthouse/revival type venue, especially one that has to be capable of playing both mag and DTS 70.

Posted by Marcel Birgelen (Member # 6801) on 02-26-2015, 10:16 AM:

It might also be as simple as hardware availability. The DA20 went end-of-sale quite a while ago and not everybody is fond of buying some refurbished hardware.

Posted by Leo Enticknap (Member # 534) on 02-26-2015, 10:56 AM:

I don't think it's that, because being a non-profit, we have a large amount of venerable and refurbished equipment in service in our booths! If I had to guess, I'd say it was because of the complexity of getting all the multiple input sources into a single CP650.

In relation to your earlier point, actually, a CP200 wouldn't look that out of place in the cockpit of a 1980s rocketship. Replace the labels under the format toggle selectors with decals that say something like "Re-entry booster, engine #1/2/3/4", and it would make the perfect prop for George Lucas's next epic!

Posted by Brad Miller (Member # 2) on 02-26-2015, 05:15 PM:

Odyssey to the rescue! Check out this neat little product they now make. 4F2410

Posted by Richard Fowler (Member # 893) on 02-26-2015, 09:15 PM:

We use the 4F2411 which is for the CP500 and it works like a charm.