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Author Topic: CP-65 problem Sam D. Chavez Film God Posts: 2153 From: Martinez, CA USA Registered: Aug 2003 posted 04-20-2009 02:09 PM                       Does the Cat. 150 center channel signal presence light when you are running Mono?  |  IP: Logged Bradley Johnson Film Handler Posts: 23 From: Newport, WA, USA Registered: Feb 2009 posted 04-20-2009 08:09 PM                     oh boy, the new card came today, put it in, and everything is working fine now. Thank God..... Keeping my fingers crossed for tonight's show. (Witch MT) had 5 people last night. I cant begin to describe how happy I am that the card was the actual problem, and not something on the Mo-board.......I can say this much,,,,,a full L-C-R-S system is a much harder beast to tame than,,,,,well,,,,Mono..... My next question is based on getting dolby level on the CP....In the CP manual it says to do this with the processor set for MONO. I set Dolby tone in this setting only to find that when Switched to SR the 222 card is slammed in the red almost all the time. Sounds,,,,not so good. I went back and set Dolby level in SR mode and now it sounds as it should.........Am I missing something here? quote: Scott Norwood If you need to borrow a cat. 85, let me know. If you want to pay shipping, I'll loan you mine for a couple of weeks. I don't believe that Dolby still sells it, but Component Engineering makes a replacement which is better in pretty much every way. Scott,,,,thank you so much for that offer, that is very generous and helpful. I now understand what a useful tool the cat 85 is. Particularly when starting completely from scratch with used gear. I think I am going to have to pony up and get the CE one,,,,,,,but ouch, they sure dont give them away,  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 04-20-2009 08:23 PM                     Bradley...go back and reset Dolby Level in MONO and nothing but on ANY Dolby processor. You are setting the level to the INPUT of the NR card(s). Once you turn the NR on, you have several things at play...one, the tracking of the NR cards themselves but in the case of SR in a movie theatre, there is also a 3dB boost applied to offset the 3dB reduction in recording level. Thus, you will see that the LEDs read higher in SR than other formats. Why the 3dB change? Well since SR offered so much more noise reduction than A...it was decided that they could record 3dB quieter and then boost it back in the processor. This increased the output level by that 3dB and thus SR can play louder than A and yet have a lower background noise. Steve  |  IP: Logged Bradley Johnson Film Handler Posts: 23 From: Newport, WA, USA Registered: Feb 2009 posted 04-21-2009 11:50 AM                     I know this most likely doesn't make a difference, but, the CP-65 in question is not fitted with cat 300s or 350s. It has a Cat 222 card with Dolby A/SR. When the 222 card goes into really hard red, it actually sounds very obviously compressed, nasty sounding compression. Best way I can describe it is the sound that a cheap audio compressor makes when driven hard with a fast release time. You can hear it pumping. After setting the Dolby tone via SR, it sounds fine. There is no compression or gain reduction devises in the system and there is a ton of headroom on the B-chain side, so I am not sure why this is happening. On a up note, last nights show went great. There is still a lot of tweaking required but, I am not sure if the patrons that have been coming to this theater can handle any more dynamic range after listing to a single cabinet on a 25 watt amp for 30 some odd years. I made some DB measurements on the old system and it had a range of about 74dba to 80dba tops. Last night, the new set up ran from 67dba to 88dba. Quite a difference, it sounded like a movie.........I will go back and reset the Dolby tone via mono and post the results. thanks all,  |  IP: Logged Sam D. Chavez Film God Posts: 2153 From: Martinez, CA USA Registered: Aug 2003 posted 04-21-2009 01:44 PM                       FYI, the Dolby level measurement at the output terminals of the Cat. No. 240 preamplifier card should be around .300 Volts AC, regardless of the format chosen. This is only important to rule out overloading the input to the 222 SR/A card. Also, don't be fooled by how the lights on the 222 card work. Two green lights mean Dolby Cal. The red lights that comes on when you go over Dolby level do not indicate clipping, just that you are over Dolby level by any amount. Kind of silly I know, bet them's the facts.  |  IP: Logged Tony Bandiera Jr Film God Posts: 3067 From: Moreland Idaho Registered: Apr 2004 posted 04-21-2009 02:42 PM                     quote: Bradley Johnson It has a Cat 222 card with Dolby A/SR. The 222SR/A card has a poor implementation of SR, so I am not surprised it sounds that way. The CP-65 at UC Irvine has it and I can hear it pumping as well...one of these days I'm gonna throw a pair of CAT300's in it to see if it sounds better. BTW, I have CAT300's for sale in the Equipment Forum...if you want a pair for your processor contact me via the info there and I'll set you up with a deal.  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 04-21-2009 05:37 PM                     Note...part of the magic of the Dolby NR process is that it only really has an effect on lower level signals. Above Dolby Level, it should not be companding anymore. The idea being, when the signal is strong, the noise is already sufficiently below the signal and no altering of the singal is needed...unlike other NR designs. It is one of the reasons that Dolby-Level is so critical to the process. Steve  |  IP: Logged Scott Norwood Film God Posts: 8146 From: Boston, MA. USA (1774.21 miles northeast of Dallas) Registered: Jun 99 posted 04-21-2009 05:42 PM                        Get Tony's cat. 300s if you can possibly afford them. The difference is significant. You can keep the 222 SR/A for Dolby A decoding, or replace it with a regular cat. 222.  |  IP: Logged Sam D. Chavez Film God Posts: 2153 From: Martinez, CA USA Registered: Aug 2003 posted 04-21-2009 11:37 PM                       350's will work as well for this purpose. 300's are A/SR, 350's are SR only if memory serves.  |  IP: Logged Bradley Johnson Film Handler Posts: 23 From: Newport, WA, USA Registered: Feb 2009 posted 04-22-2009 12:38 AM                     I think I am going to see what Tony will take to part with his Cat 300s. If the Cat 222 SR/A sounds like this in normal SR operation, then it is complete jive.  |  IP: Logged Sam D. Chavez Film God Posts: 2153 From: Martinez, CA USA Registered: Aug 2003 posted 04-22-2009 09:03 AM                       Not to unsell Tony's Cat. 300's, but it should not sound that bad using normal 222's. You may have another problem, maybe with the 222, it's not unknowm.  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 04-22-2009 11:26 AM                     I agree it should not have a particularly distorted sound on the Cat 222 but I have found the Cat 222 sound to be objectionable as have customers who pointed it out to me. I've done the side-by-side test in a CP65 and the difference when done that way was pretty clear. You ARE using Dolby Tone...right...not pink noise to set levels. Sam is quite correct too that the Cat 350s are SR only and the Cat 300s are SR and A. the CP65 will be smart enough to know when either the Cat 300s or 350s are inserted to use them for SR in preference over the Cat 222SR/A. If you do get the Cat 300s, you will have 4-channels of A-type NR in there for all of your big 70mm features Steve  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 04-22-2009 01:05 PM                        I agree with Sam; the 222sr/a is not that bad especially with exciter lamps or Jax lites. It becomes somewhat worse with a really good LED reader, especially if you are flat up to 16K. It is not important unless you have a small room, really good hf speakers and bi amping. Big room, average speakers, you won't know or care. Louis  |  IP: Logged Tony Bandiera Jr Film God Posts: 3067 From: Moreland Idaho Registered: Apr 2004 posted 04-22-2009 01:48 PM                     Louis I respectfully disagree with what you said..it doesn't matter what size of room or if you're bi-amped or not, the 222SR/A is audibly inferior. You can hear a difference on a lot of films. Older prints especially, the NR effect is not as solid. It's not necessarily a BAD card, but it just doesn't measure up against a 300/350. Dolby had to cut a lot of complexity to cram TWO Channels of SR-like NR onto that single tiny card. And Sam is right, problems with the 222 are not unheard of, Bradley may have issues with it as well.  |  IP: Logged John Hawkinson Film God Posts: 2273 From: Cambridge, MA, USA Registered: Feb 2002 posted 04-22-2009 03:36 PM                     Bradley: What test material are you using to judge the quality of your CP65 (and Cat. 222)? Are you listening on monitors or in the room itself? Also, how many turns did you have to adjust from calibrating in SR to calibrating in mono? --jhawk  |  IP: Logged

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