Film-Tech Forum ARCHIVE: CP65 - non-sync settings

This is topic CP65 - non-sync settings in forum Film Handlers' 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=1;t=008850

Posted by Andy Frodsham (Member # 4061) on 07-28-2007, 12:43 PM:

I'm slightly confused by the two available non-sync settings on our Dolby CP65! Am I right to understand that the standard setting merely sends the right and left non-sync sound to the respective speakers behind the screen? If so, I assume that the surround speakers receive no signal whatsoever? What about the 2:4 setting? I believe this sends information to each of the speakers - but what is it (stereo with ambience etc)?

The jumper settings on the Cat 443 allow for the switching on or off of the surround speakers in non-sync. When, and why, would one need to do this in addition to the previous settings?

Posted by Brian Guckian (Member # 1678) on 07-28-2007, 02:02 PM:

The jumper sets either two-channel L/R stereo reproduction (no matrix decoding) or four-channel L/C/R/S matrix decoding.

If you set the jumper for 2:4 matrix decoding and have Optical Bass Extension, you can reproduce subwoofer information, giving you 4.1, which can be useful.

It's best nowadays to set your non-sync for 2:4 decoding given that the majority of material off CD is likely to be Dolby Surround encoded. But even if not, the 2:4 decoder will still pass through a simple two-channel L/R stereo signal, no essentially all options are covered by using the 2:4 jumper position.

I don't have sufficient information right now to answer the second part of your question, but hope the above helps.