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-   -   Carbon is not -18dBFS like normal HD? Also, how to use S/PDIF? (https://duc.avid.com/showthread.php?t=415024)

CoreRec 04-18-2021 02:31 PM

Carbon is not -18dBFS like normal HD? Also, how to use S/PDIF?
 
Looking at upgrading from an HD6 Accel system w/ HD I/O and Symphony I/O that's been extremely reliable.

Like others, I tried HDX, but found the latency way too high once plugins were added (44.1). Plus the fan was unusably noisy.

The latency numbers with Carbon are less than half what HDX shows - very impressive!

I have some questions that I can't find answers to (or are curious oversights):

1. How can I use S/PDIF with Carbon? I can't see a way and that would be a real bummer of an omission - possibly deal breaker
2. How can it be expanded beyond the 24 I/O (I usually use 28 ins, but 30 when the band has a keyboardist)
3. The specs make it appear that Carbon is -20dBFS rather than -18dBFS like normal Digi/Avid IOs - is that right?
4. Does it possibly have SRC available on the ADAT I/O like 192s?
5. How long before preamp recall will be enabled like PRE and MTRX?

Thanks!

Matt Hepworth 04-22-2021 06:13 PM

Re: Carbon is not -18dBFS like normal HD? Also, how to use S/PDIF?
 
Interesting it's not -18dBfs. 24 I/O is definitely a tough spot if you can't expand. Maybe Kyle will chime in on some of the other questions.

originalscottyg 04-23-2021 12:22 PM

Re: Carbon is not -18dBFS like normal HD? Also, how to use S/PDIF?
 
Almost all the other Avid converters (192s, HD I/Os, Omni, MTRX, etc., mbox series excluded) have calibrate-able analog I/O. So you can set up the analog side to be -18, -20, -16, etc. I'd be curious to know whether Carbon's analog I/O can be calibrated.

BScout 04-23-2021 01:36 PM

Re: Carbon is not -18dBFS like normal HD? Also, how to use S/PDIF?
 
1) You can't directly. You could get a ADAT to AES converter (like from RME). AES and SPDIF are cross compatible (different connector and different impedance but otherwise the same so they can be changed passively with a cable)
2) Can't at the moment (if you still want it to run with the Carbon features)
4) If it had SRC, there would be an option box in the hardware setup. It doesn't have that. And SRC isn't mentioned. So nope.

Kyle Splittgerber 04-23-2021 03:52 PM

Re: Carbon is not -18dBFS like normal HD? Also, how to use S/PDIF?
 
Quote:

Originally Posted by CoreRec (Post 2599932)
Looking at upgrading from an HD6 Accel system w/ HD I/O and Symphony I/O that's been extremely reliable.

Like others, I tried HDX, but found the latency way too high once plugins were added (44.1). Plus the fan was unusably noisy.

The latency numbers with Carbon are less than half what HDX shows - very impressive!

I have some questions that I can't find answers to (or are curious oversights):

1. How can I use S/PDIF with Carbon? I can't see a way and that would be a real bummer of an omission - possibly deal breaker
2. How can it be expanded beyond the 24 I/O (I usually use 28 ins, but 30 when the band has a keyboardist)
3. The specs make it appear that Carbon is -20dBFS rather than -18dBFS like normal Digi/Avid IOs - is that right?
4. Does it possibly have SRC available on the ADAT I/O like 192s?
5. How long before preamp recall will be enabled like PRE and MTRX?

Thanks!

Hello.
1. We're planning to implement Optical S/PDIF support on the ADAT ports, but I can't say when that will be available.
2. Like BScout said, you can't at this time. Max is currently 25 inputs x 34 outputs.
3. Carbon has +24 dBu max input/output level which translates to -20 dBfs of headroom with a +4 dBu signal. HD I/O has less headroom than Carbon as it has a max input/output level of +22 dBu.
4. No SRC
5. Can't provide a time estimate, but it's a very high priority feature.

CoreRec 06-12-2021 02:29 PM

Re: Carbon is not -18dBFS like normal HD? Also, how to use S/PDIF?
 
Quote:

Originally Posted by Kyle Splittgerber (Post 2600449)
Hello.
1. We're planning to implement Optical S/PDIF support on the ADAT ports, but I can't say when that will be available.
2. Like BScout said, you can't at this time. Max is currently 25 inputs x 34 outputs.
3. Carbon has +24 dBu max input/output level which translates to -20 dBfs of headroom with a +4 dBu signal. HD I/O has less headroom than Carbon as it has a max input/output level of +22 dBu.
4. No SRC
5. Can't provide a time estimate, but it's a very high priority feature.

So I need to set my Apogee to -20dBFS to match Carbon?
I'm not quite sure how this works with the way you worded it. Normally I set everything to -18dBFS which is +22dBu I believe.

JFreak 06-12-2021 03:34 PM

Re: Carbon is not -18dBFS like normal HD? Also, how to use S/PDIF?
 
Quote:

Originally Posted by CoreRec (Post 2604166)
So I need to set my Apogee to -20dBFS to match Carbon?
I'm not quite sure how this works with the way you worded it. Normally I set everything to -18dBFS which is +22dBu I believe.

Yes. And it is always good to check the specs of any interface you are using, like DigiDesign 96 was/is 14, 192 was/is 18 and these new ones are 20. Apogee Symphony mk2 that I am using at home can be software calibrated to 12/14/16/18/20

BScout 06-13-2021 02:31 AM

Re: Carbon is not -18dBFS like normal HD? Also, how to use S/PDIF?
 
Despite this inaccurate "knowledge base" article, the MTRX has a 30dBu possibility. And the MTRX Studio has a 24dBU possibility.

https://avid.secure.force.com/pkb/ar...-Output-Levels

(anyone want to to give Avid the heads up they have it wrong on the MTRX -- kind of embarrassing)

JFreak 06-13-2021 02:53 AM

Re: Carbon is not -18dBFS like normal HD? Also, how to use S/PDIF?
 
dBu and dBFS are two different things, albeit connected to the same thing - calibration.

It is not inaccurate to say (in a knowledgebase article) that calibration of -18dBFS will provide +4dBu analog output, meaning unity levels are +22dBu. So if a box is capable of +24dBu it can be calibrated to -20dBFS and if there is extra "capability" it is just headroom, I have never heard of anyone wanting to calibrate lower than -20dBFS.

BScout 06-13-2021 10:48 PM

Re: Carbon is not -18dBFS like normal HD? Also, how to use S/PDIF?
 
Quote:

Originally Posted by JFreak (Post 2604189)
dBu and dBFS are two different things, albeit connected to the same thing - calibration.

This I know. Read what I wrote again understanding the specs of the equipment involved. And how they are stated in the KB.
The Knowledge Base article is wrong. The MTRX (full) is 30 dBu capable for AD. Looking at 24 channels of it.

-20dBFs calibration is standard for theatrical post (what I work in).

Whether you (or I) calibrate to 30dBu ( -26dBFs for +4) I know classical/location recordist who do and the MTRX/DAD aren't the first able to do this. Wrong is wrong.


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