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» Film-Tech Forum   » Operations   » Digital Cinema Forum   » Hearing Impaired tracks (Page 1)

 
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Author Topic: Hearing Impaired tracks
Richard May
Phenomenal Film Handler

Posts: 1038
From: Floral Park, NY USA
Registered: Aug 2004


 - posted 04-23-2017 10:48 AM      Profile for Richard May   Email Richard May   Send New Private Message       Edit/Delete Post 
If there is no indication of an H/I track on the DCP title, does this mean there actually is none on the movie? If so, where do you pick up audio for H/I?

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Harold Hallikainen
Jedi Master Film Handler

Posts: 766
From: Denver, CO, USA
Registered: Aug 2009


 - posted 04-23-2017 11:25 AM      Profile for Harold Hallikainen   Author's Homepage   Email Harold Hallikainen   Send New Private Message       Edit/Delete Post 
I believe that if HI is not in the package name (as specified at http://isdcf.com/dcnc/ ), there is no HI track in the DCP. In that case, you can use an LCR mix from the sound processor. I believe all cinema sound processors have an HI output.

Harold

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Richard May
Phenomenal Film Handler

Posts: 1038
From: Floral Park, NY USA
Registered: Aug 2004


 - posted 04-23-2017 11:31 AM      Profile for Richard May   Email Richard May   Send New Private Message       Edit/Delete Post 
I was going to do that but we have the Doremi Fidelio system with captive view. How would I input the H/I from the processor and still have the captive working?

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Harold Hallikainen
Jedi Master Film Handler

Posts: 766
From: Denver, CO, USA
Registered: Aug 2009


 - posted 04-23-2017 12:06 PM      Profile for Harold Hallikainen   Author's Homepage   Email Harold Hallikainen   Send New Private Message       Edit/Delete Post 
That is an issue. The HI output of sound processors is generally analog. There are fairly low cost analog to digital converters with S/PDIF outputs that I THINK could drive the Fideleo. Some people have used an AES splitter to drive the Fideleo with the center channel (first channel of second AES pair from server to sound processor). You can make an AES splitter with six resistors per pair. I did a design a few years ago and built a few units by hand with three RJ45 connectors on each. We sued it to drive a couple sound processors at once as we tried out new systems in a theater. Some day I may do a PCB for it.

Harold

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Jim Cassedy
Phenomenal Film Handler

Posts: 1554
From: San Francisco, CA
Registered: Dec 2006


 - posted 04-23-2017 01:18 PM      Profile for Jim Cassedy   Email Jim Cassedy   Send New Private Message       Edit/Delete Post 
quote: Harold Hallikainen
You can make an AES splitter with six resistors per pair.
I needed to do something similar a couple of years ago. I used
this circuit, which I found on the internet, and apparently uses
one less resistor than Harold's, but it worked fine for me:
 -

This situation was a bit different than what Harold was doing,
since I needed to go from AES to SPDIF, but if you poke around
on the 'net, you might find a circuit that works for you.

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Carsten Kurz
Film God

Posts: 3781
From: Cologne, NRW, Germany
Registered: Aug 2009


 - posted 04-24-2017 05:28 AM      Profile for Carsten Kurz   Email Carsten Kurz   Send New Private Message       Edit/Delete Post 
I guess a cheap S/P-DIF Audio ADC is the better way to go for the typical cinema processor with analog only HI output.

e.g. http://www.ebay.com/itm/Analog-RCA-Stereo-To-Optical-Audio-Coax-S-PDIF-Digital-Audio-Forma t-Converter-/191566028140?hash=item2c9a399d6c:g:SwgAAOxyhodRvN-F

Don't mistake it for one of those many even cheaper S/P-DIF digital to analog audio converters available on ebay or Amazon.

- Carsten

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Steve Guttag
We forgot the crackers Gromit!!!

Posts: 12213
From: Annapolis, MD
Registered: Dec 1999


 - posted 04-24-2017 08:24 AM      Profile for Steve Guttag   Email Steve Guttag   Send New Private Message       Edit/Delete Post 
It is definitely a flaw in the Fidelio system. If you want HI on trailers, Blu-rays or any DCP that doesn't have a dedicated HI track, then you have to D-A the ADA signal and then A-D it back with the derived HI combined with the supplied VI-N track. This makes the Fidelio system yet more expensive (and a hassle to install). Up until recent firmware updates, if you over drove the signal in a Fidelio transmitter, it would reset itself (repeatedly too) so you had to really mind your levels.

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Chris Daigle
Film Handler

Posts: 24
From: Gardner, MA USA
Registered: Dec 2012


 - posted 12-29-2017 01:10 PM      Profile for Chris Daigle   Email Chris Daigle   Send New Private Message       Edit/Delete Post 
After installing the new USL/QSC Hearing Impaired/Closed Caption system we're having an issues with getting the HI track to output during the trailers. On two of our screens we have USL JSD-60 sound processors and those are working fine. On the others, I have Dolby CP650's connected to a USL DAX-602 and the HI signal doesn't kick in until the feature starts. Is there something I have to do to get the HI signal from the trailers to output from the DAX?

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Dave Macaulay
Film God

Posts: 2136
From: Toronto, Canada
Registered: Apr 2001


 - posted 12-29-2017 01:40 PM      Profile for Dave Macaulay   Email Dave Macaulay   Send New Private Message       Edit/Delete Post 
If the HI track is a mixdown from the analog audio, it will be present for all content. If it's using the HI/VI AES digital channel then only content with HI/VI tracks will be heard... and trailers usually do not have them. It is normal for captioning and HI/VI systems that use the data from a DCP to only work during features and very occasionally on trailers that include the data. I don't know if there's any push to require this for all cinema content.

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Harold Hallikainen
Jedi Master Film Handler

Posts: 766
From: Denver, CO, USA
Registered: Aug 2009


 - posted 12-29-2017 04:34 PM      Profile for Harold Hallikainen   Author's Homepage   Email Harold Hallikainen   Send New Private Message       Edit/Delete Post 
As I recall, the CP650 has an analog HI output that is the sum of left, center, and right. You can use this to drive the IRC-28C instead of using the HI output of the HI output of the DAX-602, which is AES/EBU channel 7 and will only have audio if there is HI audio in the DCP.

Harold

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Sean McKinnon
Phenomenal Film Handler

Posts: 1574
From: Peabody Massachusetts
Registered: Sep 2000


 - posted 12-30-2017 07:00 PM      Profile for Sean McKinnon   Email Sean McKinnon   Send New Private Message       Edit/Delete Post 
I would use the HI output from the co-650 to drive the HI emitter so that you get the alt content and trailers. Also I like to use a mixer to mix the HI into the VI so or send the HI to one ear and VI to the other so the customer can set their own mix.

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Stephan Shelley
Jedi Master Film Handler

Posts: 701
From: castro valley, CA, usa
Registered: Nov 2014


 - posted 12-30-2017 07:04 PM      Profile for Stephan Shelley   Email Stephan Shelley   Send New Private Message       Edit/Delete Post 
The new USL head sets allow mixing of the HI & VI. The fedelo system allows the receivers to be programed to receive both HI and VI and mix it.

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Harold Hallikainen
Jedi Master Film Handler

Posts: 766
From: Denver, CO, USA
Registered: Aug 2009


 - posted 12-30-2017 11:26 PM      Profile for Harold Hallikainen   Author's Homepage   Email Harold Hallikainen   Send New Private Message       Edit/Delete Post 
The QSC/USL model that allows the user to mix HI an VI is the IRH-281.

Harold

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Sean McKinnon
Phenomenal Film Handler

Posts: 1574
From: Peabody Massachusetts
Registered: Sep 2000


 - posted 01-01-2018 02:43 PM      Profile for Sean McKinnon   Email Sean McKinnon   Send New Private Message       Edit/Delete Post 
A lot of the systems we do are heavy in alternate content. It would be nice if the fidelio had an analog input that you could mix with the HI and VI as needed b

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Carsten Kurz
Film God

Posts: 3781
From: Cologne, NRW, Germany
Registered: Aug 2009


 - posted 01-02-2018 06:09 AM      Profile for Carsten Kurz   Email Carsten Kurz   Send New Private Message       Edit/Delete Post 
Yes - a great flaw with the Fidelio system. Some locations use an external small A/D converter to feed the processor HI output into the Fidelio transmitter.

- Carsten

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