Film-Tech Forum ARCHIVE: Connecting consumer grade video projector to sound rack

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Posted by Robert E. Allen (Member # 1351) on 04-07-2014, 03:55 AM:

I am going to install a consumer grade video projector in my small (37 seat) auditorium. I'm not a tech so I need some advise as to what is needed to run the sound from this video projector through the theatre sound rack. It's a Dolby Stereo CP55.

Posted by Jonathan Wood (Member # 4614) on 04-07-2014, 04:09 AM:

Hi Robert , I would have thought it depends on what else you are running And what you need sound wise in the auditorium ? Are you using da 20 for eg? In the most basic set up you could attach the line outs of your source (BD / DVD) deck to the non sync inputs on the rear of the cp. you would need a twin phono to bare leads which u would solder to the non sync tags. This means you would loose your existing non sync tho? What is your set up ? There are most likely no audio outs on your projector.

Posted by Scott Norwood (Member # 30) on 04-07-2014, 07:35 AM:

Non-sync will get you sound, but it will not get you L/C/R/S decoding on a stock CP55.

It will instead give you left/right/surround with no center channel. This is not ideal (since dialogue sounds weird when it comes from two channels at once). The processor can be modified to decode the sound properly, but it is a fairly involved modification that you would want to have a technician do. How to do it depends on if you have a DA20 and/or cat. 222 SR/A card installed.

If you have a playback device with discrete 6-channel outputs (like the Oppo Blu-Ray players), another option is to do the DA20 modification and feed the 6-channel output from the player into the DA20 input (or the bypass input on the DA20 if you already have one installed).

Posted by Gordon McLeod (Member # 33) on 04-07-2014, 09:54 AM:

Even modified there can be a issue on the sub when routed through the NonSync Input
If the signal source is LT RT and no film requirements I connected to the input of the CAT150 like the way the SR adapter did

Posted by Mark Gulbrandsen (Member # 72) on 04-08-2014, 11:28 AM:

It seems to me that the pro logic required to properly decode DVD's and Blu-Rays is still considerably different then what a CAT 150 does and that using a CAT 150 still may not work correctly. The best solution is to get a player that has the decoder built in. Players such as the Oppo have this feature. Then you just feed the 5.1 signals in to the Aux 6 track input.

Mark

Posted by Robert E. Allen (Member # 1351) on 04-08-2014, 01:48 PM:

Thanks for the input guys. I'll pass this on to my son who is my tech mgr.

Bob