Film-Tech Forum ARCHIVE: CP750 channels mixed up

This is topic CP750 channels mixed up in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=16;t=001713

Posted by Dave Macaulay (Member # 813) on 11-27-2013, 03:32 PM:

Has anyone seen this? CP750 with non-sync on format 61, when switched ftom n/s to Dig 1 for server sound - the channel assignments are mixed up: centre channel coming from left surround, etc.

Posted by Ian Freer (Member # 1940) on 11-27-2013, 05:25 PM:

I had this recently, but not with CP750.
I had Doremi ShowVault, Dolby DMA8+ and CP650, Barco 4K32.

Was totally confused and would never had believed it if I hadn't seen/heard it myself.

Initially I thought it was the DMA8+ so rebooted that, no change. From memory I then started checking the channel mapping in the Doremi, and the results were just weird and confusing. I think even rebooting the Server resulted in still no change.

Eventually I did what I probably should have done first, shut down everything, Server, Projector and DMA.

Everything was good upon reboot. VERY strange...

This lead me to think it was probably the IMB that needed rebooting, but it'd be interesting to know what other equipment you had and how you fixed your occurrence Dave...

It was definitely Centre Channel coming from Left Surround, something came out of Right and the surround speakers I think, but also a couple of channels were completely missing too...

Posted by Geoff Newitt (Member # 6663) on 11-28-2013, 08:25 AM:

Right at the start of this year I had a CP750 go nuts - all the channels jumbled up. Reboots of CP750, Doremi Showvault and IMB were no use. The CP had been installed for all of about two months, is left on 24/7 on a UPS

I was sufficiently puzzled that I used the 'rotate' function to move pink noise around the channels; sure enough, it came out in a random sequence, rather than travelling around the room in the usual fashion.

The only solution I could find was to reinstall the firmware, which worked a treat.

Alas, the Back Surround Right speakers hadn't taken kindly to being fed Sub, and had to be replaced.

Posted by Martin Brooks (Member # 1269) on 11-30-2013, 02:08 PM:

Around the time of the release of Hugo and Rise of the Planet of the Apes, I was in two different theaters in which the center channel was coming out of the left front. Maybe this was the reason. At the time I just assumed that the installer was the same for both theaters (which were part of the same chain) and got his/her colors mixed up. Don't know how they EQd the place that way though.