Film-Tech Forum ARCHIVE: CP750 Sorround Ex

This is topic CP750 Sorround Ex in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by Annli Com (Member # 8266) on 01-24-2015, 08:57 AM:

Dear All
My Samll Doubts The PCM 5.1 Discrete and Dolby Sorround Exx Is Same Outputs in Cp 750 Processor ?
Which Format For Good in 5.1 Movies In Dolby CP 750 ,Our Theatres 7.1 Speaker System. Kindly Advice Me

Posted by Steve Guttag (Member # 268) on 01-24-2015, 10:51 AM:

EX never really made it into DCinema. The CP750 can certainly decode it but I don't recall any DCinema movies so encoded (6.1). Run 5.1 movies in 5.1 and 7.1 movies in 7.1. The CP750 will have the correct sound coming from the various speakers.

Posted by Dave Macaulay (Member # 813) on 01-24-2015, 12:00 PM:

I didn't know a CP750 could handle EX, but I haven't heard of any encoded content either.
The CP750 5.1 mode sends SL to the SL and BSL outputs, same idea with right. Using the 7.1 mode uses four discrete surround channels. The source for BSL and BSR is channels 7 and 8, AES pair 4 on the CP750 Dig1 4xAES digital input. pair 4 is officially the HI/VI audio on a DCP so you have to do something to move the server output AES pair 6 (ch 11/12) over to the CP750 pair 4 input.
Of course that may change if SMPTE metadata steered audio routing becomes standard...
Some servers swap channels around for this, Odyssey makes input cards to handle it as well. The Odyssey cards also have an output for the otherwise lost HI/VI audio so you can add a D-A converter and supply it to your patrons.

Posted by Steve Guttag (Member # 268) on 01-24-2015, 11:50 PM:

The CP750 will let you use "Digital 2" as the D/A converter for HI/VI-N and send them out the "AUX" outputs. You just need (or should use) a balun to convert the AES3 to AES3-id (110-Ohm balanced to 75-Ohm unbalanced).