Film-Tech Forum ARCHIVE: CP650 mono surrounds (not intentionally)

This is topic CP650 mono surrounds (not intentionally) in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Dominic Espinosa (Member # 2122) on 08-06-2012, 01:12 PM:

Heh all,

So I have a new one. This is on a CP650 with a CM680 monitor/crossover and QSC amps. All D-sub connectors in the chain from proc to mon/xmover to amps.
The 650 is running SW version 2.5.0.0

Listening to the movie you'd guess no surrounds.

Ran pink noise and found very weak signal (doesn't register on SPL meter but can be heard) on both surround channels simultaneously no matter which surround channel is active (Ls, Rs, BsL, or BsR).

Verified at the monitor that I can hear pink noise on either surround channel when listening to the processor outputs, again, when either surround channel is active, including the back surround channels.

Thoughts? Thanks in advance, guys!

Posted by Tony Bandiera Jr (Member # 2365) on 08-06-2012, 01:21 PM:

Dominic:

How did you run pink noise? If via a film loop you'd better not hear the surrounds loud as it means the A chain is out of alignment. CAT 151 center/surround would be the "proper" loop to use.

If you did it via the CP-650's built-in pink noise generator which steps through the channels one at a time, what are the results? Do you hear the pink at each surround channel at the proper time? Are the levels low, high or normal on each channel? Are the levels ok on the "Processor" side but low on the "AMPS" side? Or low on both sides?

Do you have a CAT 790 installed? If so, remember that to get the surrounds to play you must have the Odyessy output board set or custom cabling to get the surrounds from the option I/O connector. If you can, snap a pic of the 650's backside showing the cabling and put it on here.

Did this situation pop up suddenly or has it always been that way?

Lots of questions but I (we) need the answer to all of them to really be able to help.

Posted by Dominic Espinosa (Member # 2122) on 08-06-2012, 02:53 PM:

Tony to the rescue!

quote: Tony Bandiera Jr
How did you run pink noise?

Via the CP650's built in pink noise generator.

quote: Tony Bandiera Jr
what are the results?

Everything is normal until we hit the surrounds. When we get to Rs, BsR, BsL, and Ls the pink noise is very quite and comes out of the Rs and Ls simultaneously. I can hear it in the monitor when listening to the amp outputs and also the processor outputs.

quote: Tony Bandiera Jr
Do you have a CAT 790 installed?

Yes, all is hooked up in this house the same as the other 11 just like it.

quote: Tony Bandiera Jr
Did this situation pop up suddenly or has it always been that way?

It was fine when a few months ago when we switched from film to Sony digital. I noticed it while checking SPL after replacing a burnt subwoofer.

Thanks again, Tony!
--dom

Posted by Tony Bandiera Jr (Member # 2365) on 08-06-2012, 04:13 PM:

Ok, that narrows it down..but to trouble shoot this is gonna take a bit of work. [Smile]

When you have some time, swap the CAT 790 with a house that is working properly and see what happens. **Mark the cards with the theatre number so you don't mix them up**. If the problem clears up on the bad house and shows up on the formerly good house then the 790 is bad. Get your vendor to get a 790 repair-exchanged.

A second possibility is a problem with the monitor. Again, if you can swap from one house to another that will pinpoint the problem.

A third but less likely possibility (and yes it can affect the input and output sides) is a fault with the amplifier.

Posted by Ian Freer (Member # 1940) on 08-06-2012, 09:10 PM:

I came across a similar problem recently. A CP650D (no Cat790) died so the cinema changed it out to a spare they had. The spare had a 790... So the surround wiring was coming off the main output connector not the option I/O. I re-wired the surrounds and it's all good now...

You mention the wiring is the same as the other 11 CP650's. Could they be CP650D's and when you installed DCP a Cat790 was added but the surround wiring was not changed?

Cheers,
Ian

Posted by Dominic Espinosa (Member # 2122) on 08-09-2012, 03:07 PM:

Alrighty, fellas.

I have tried swapping the cat 790 and the monitor/crossover. No dice.
I disconnected from the amp and checked just the processor output, same problem.

The surround seems to be coming off the main output of the CP650.

They're all CP650D's.

Posted by Tony Bandiera Jr (Member # 2365) on 08-09-2012, 03:31 PM:

Ok, next step I need to see the wiring as connected to the back of the 650. Take at least one clear pic showing the entire backside of the processor.

If you do not have any audio cabling (or the Odyssey board set) coming off of the option connector then it has been miswired. (If so, sounds like ALL of your installs are miswired.)

You should have a set that looks something like this:

The board on the left goes to the main Audio out connector and the board on the right goes to the Option connector.

If you just have the servers' AES audio cable connected to the option connector then it is 100% positively miswired.

Thankfully the fix is relatively easy (but not cheap, as the board sets are around 100-150 each) but once the boards are installed a quick B-chain tweak will get you to 100%.

EDIT: Are all your houses D-Cinema or are they film? What is the setup with the bad house?

Posted by Ian Freer (Member # 1940) on 08-09-2012, 05:40 PM:

How is the audio from the Sony DCP getting into the CP650? If it is going in to the Option I/O, then a Cat790 must have been installed. This would result in the issue I mentioned in my previous post; after the Cat790 was installed the surrounds were not re-wired to the Option I/O but left on the main output connector...

If the Sony DCP is going through an D2A converter of some sort into Format 11 Analogue input then I am wrong and carry on following Tony's suggestions...

Posted by Tony Bandiera Jr (Member # 2365) on 08-09-2012, 06:45 PM:

Ian, yes you are right, but to be clear:

If a CAT 790 is in play, no matter how the server is being fed in (AES or Analog Format 11) you MUST use the board set or make up a special cable to get the surround outputs. That holds true BTW even for film too.

If there is no CAT 790 and the server outputs are going into the analog inputs you can still get the surrounds through the main outputs.

Now we need Dominic to do his homework and get the pic up so we can see what he's got.

Posted by Ian Freer (Member # 1940) on 08-09-2012, 07:23 PM:

Hi Tony

Yes, sorry I wasn't clear. I was trying to imply that identifying which input was being used was a simple first step to identifying if a Cat790 had been installed (as this is the important piece of info we are missing)...
i.e. IF input is Option I/O then there MUST be a Cat790 and Surround Outputs MUST be wired from Option I/O too...

Of course simply stepping through the menu will eventually tell you what option cards are installed too...

Ian

Posted by Sam D. Chavez (Member # 1841) on 08-10-2012, 12:58 AM:

Let's back up a minute here.

Dominic says,

"The surround seems to be coming off the main output of the CP650."

They're all CP650D's."

Sounds like he's saying the surround wire(s) to the amps are coming off the main output along with L,C,R,.

So, if it has a 790 board installed it is not a CP650D any more, it is a 650 and the surround wiring needs to be moved up to the correct terminals on the I/O port. The Odyssey board is a big help in this regard.

Posted by Manny Knowles (Member # 1171) on 08-10-2012, 09:07 AM:

Just some moral support [thumbsup]

Posted by Dominic Espinosa (Member # 2122) on 08-10-2012, 03:24 PM:

Well, gentlemen, I'm kicking myself now!
They're all hooked up properly.
We DO have the surrounds coming off the Odyssey board. However the monitor/crossovers were never switched to listen to the second input.
On the back of the CM680 there is an 8 position dip switch. 1-4 on for normal srrounds, 5-8 on for EX, which is where the surrounds would come out of in this case. Durp.

Thanks to all of you guys for your assistance!

Posted by Tony Bandiera Jr (Member # 2365) on 08-10-2012, 04:21 PM:

Glad to hear you fixed it and you're welcome. [Smile]