Film-Tech Forum ARCHIVE: Dolby A question

This is topic Dolby A question 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=007167

Posted by Matthew Taylor (Member # 2310) on 05-06-2005, 05:24 PM:

I am thinking of buying a CP-50 for my home setup. I would like to know if Dolby A noise reduction would work on modern prints. I understand that modern prints are encoded for SR, so would I still get noise reduction with a CP-50?

If not, I may as well just get a cheaper consumer pro-logic system to give me some sort of surround sound.

Posted by Richard May (Member # 2627) on 05-06-2005, 05:41 PM:

Dolby SR prints can still be played in (04) Dolby A and still get the correct Dolby A noise reduction.

Posted by David Stambaugh (Member # 1102) on 05-06-2005, 06:18 PM:

Someone correct me if I'm wrong: Dolby says that playing SR through an A decoder is "compatible". But SR through A has never sounded very good to me. [Confused]

Posted by Darryl Spicer (Member # 711) on 05-06-2005, 06:31 PM:

It's the other way around. You can play SR prints in A or SR but you can not play A prints in SR and expect it to sound very good.

Posted by Richard May (Member # 2627) on 05-06-2005, 06:58 PM:

Darryl is correct. I have never had a problem playing an SR print in Dolby A. Obviously, you don't get the benefit of SR playback when you do that. That may be why it didn't sound so great.

Posted by Gordon McLeod (Member # 33) on 05-06-2005, 07:47 PM:

The fact that you get a good preamp and academy filter and eq in the cp50 is by far better than a home brew
If you want SR then just plug in 2 cat 280T's

Posted by Gilbert Travin (Member # 2138) on 05-09-2005, 06:14 AM:

Hi Matthew !

If you use a cheap home theater amplifier to decode surround sound (in prologic mode) you must use the CP 50 "Rt+Lt" rear outputs : the level of these outputs match with amplifier inputs. And sub channel is also decoded ! With this method you profit of A or SR noise reduction, but you don't profit of CP-50 front speakers equalization (Cat 64) ; for mono prints, you don't profit of the academy 8 kHz filter.
The second method consists to use a home theatre amplifier with direct inputs (not cheap, alas !!!) : you connect the four ouput channels + the sub channel of the CP-50 to the 6-direct-input of your home theatre amplifier (surrounds Left and Right are wired together !) and you profit of all CP-50 possibilities [Big Grin]