Sync X - Help Understanding.

[PhilipKapadia]

Hello all, I'm sorry for the (super basic) question. I really want to understand the Sync X line of devices, and I'm struggling to find online info or other forum threads which explain this.

In this hypothetical scenario, I want to set up a Pro Tools system for video post-production.

I would have a:
- Pro Tools machine
- A Video I/O device like a Blackmagic UltraStudio 4K (for SDI/HDMI signal to a monitor)
- An Audio Interface going into my speakers

I'm assuming the Sync device somehow synchronises the Audio Interface to the Video I/O device, but I'm not 100% sure. How would the audio interface and video I/O devices sync together without drifting, without a Sync box? How is the Sync Box physically connected to the Video I/O and Audio Interface... Through SDI, XLR?

Really appreciate any help!

[Frank Kruse]

Here's a good primer for how to set it up

https://www.production-expert.com/pr...ools-explained

(Note that the graphics in the article is missing an essential connection from the sync generator to the video hardware. They only show one "cable" to the sync device. Without it the setup does practically nothing. They should fix that. I think the text however is correct)

Oh, and you need an AVID audio interface and HD card with the serial connection. The whole genlock setup won't work with a third party interface.

The Sync X has the video sync generator built in. That's the main difference to what's described in the article.

[PhilipKapadia]

Thanks for sending that. In short, I understood the setup would be:

Blackmagic Sync Generator - Sync X
HDX - Sync X
Sync x - Video BOB
Sync x - Audio Interface

Here's where I have further questions:

Why do you need an HDX card to plug the sync generator into Pro Tools? I assume that allows Pro Tools to 'control' the device, change settings, etc?

"hy do you need a 'sync generator' to plug into the Sync X - I thought the point of the Sync X was to generate that house sync signal?

Which audio interfaces have BNC connections for video sync signals? Could you patch LTC through an audio interface's XLR, for example?

Why couldn't you have just a video BOB with XLR outs, or just demux the audio out of the 16 channels of an SDI signal, instead of a separate audio interface and video BOB setup - I assume this setup would limit you from patching in outboard audio gear...?

[devinemke]

Originally Posted by PhilipKapadia

Why do you need an HDX card to plug the sync generator into Pro Tools? I assume that allows Pro Tools to 'control' the device, change settings, etc?

Correct. The serial connector on the HDX card connects to the Sync X so that you can control your clock settings in Pro Tools.

Originally Posted by PhilipKapadia

Why do you need a 'sync generator' to plug into the Sync X - I thought the point of the Sync X was to generate that house sync signal?

You don't necessarily need an external sync generator. You can use the Sync X as the clock master for your entire A/V system. If you are working in a larger facility/studio that has a common "house sync/black burst" then you should use that to drive the Sync X.

Originally Posted by PhilipKapadia

Which audio interfaces have BNC connections for video sync signals?

Modern Avid i/o devices have loop sync BNC ports, where you can daisy chain multiple devices togther, and then patch back to the Sync X to close the loop.

Originally Posted by PhilipKapadia

Could you patch LTC through an audio interface's XLR, for example?

LTC is strictly for positional reference, not for clocking reference. That is why you still need the Sync X or some other sync generator to act as the clock master for your entire system.

Originally Posted by PhilipKapadia

Why couldn't you have just a video BOB with XLR outs, or just demux the audio out of the 16 channels of an SDI signal, instead of a separate audio interface and video BOB setup - I assume this setup would limit you from patching in outboard audio gear...?

The only Avid audio device that I am aware of that can mux/demux audio from SDI is the Dual SDI/HD/3G Card for the MTRX system.

Hope this helps

[smurfyou]

Originally Posted by PhilipKapadia

Why do you need an HDX card to plug the sync generator into Pro Tools?

That question has been plaguing me for years.

[Frank Kruse]

Originally Posted by PhilipKapadia

Why do you need an HDX card to plug the sync generator into Pro Tools? I assume that allows Pro Tools to 'control' the device, change settings, etc?

Not only to remote control the settings. ProTools needs to "know" when exactly to correlate the position of the audio and video in your timeline to the external clock edge. There has to be some kind of coms between the audio interface and the PT app to maintain the timing.

As in: here's the frame edge, play your audio sample number XXXX and video frame XXX NOW!

That's the main error in the article I posted. Without all connections and hardware attached the clock becomes useless. Yes it will send something to some of the hardware but they will not interlock unless every connection is made. Any yes, the SYNC X will spare you the extra generator but with a heavy price tag ;-)

So for real frame edge interlock you need to go all in with AVID hardware. HDn card is minimum and an AVID audio interface and SYNC HD. And no, connecting wordclock only instead of video ref will not do the trick.

[its2loud]

You should also ask yourself if this something you really need. Many people use video playback from Pro Tools without a SyncX or Sync HD without any problems at all.

[PhilipKapadia]

Originally Posted by its2loud

You should also ask yourself if this something you really need. Many people use video playback from Pro Tools without a SyncX or Sync HD without any problems at all.

It is definitely not something I need; I am just trying to understand what exactly this device does.

Originally Posted by Frank Kruse

Not only to remote control the settings. ProTools needs to "know" when exactly to correlate the position of the audio and video in your timeline to the external clock edge. There has to be some kind of coms between the audio interface and the PT app to maintain the timing.

Could that not be done through Thunderbolt, USB 3, or a direct PCIE port?

Originally Posted by PhilipKapadia

I really want to understand the Sync X line of devices

Thanks, everyone, for explaining... In short, I understand this device is used to synchronise the clocks of video and audio hardware. E.G. a Blackmagic video BOB, and an Audio Interface.

Are there other environments where this device is needed apart from the scenario I mentioned above?

Originally Posted by devinemke

The only Avid audio device that I am aware of that can mux/demux audio from SDI is the Dual SDI/HD/3G Card for the MTRX system.

You could demux audio from an SDI signal through a Blackmagic SDI to Analogue audio converter: https://www.blackmagicdesign.com/uk/...miniconverters

But this kind of separate video I/O and audio I/O would be useful in a film voiceover suite where you need video I/O to feed reference monitors and displays for the talent and an audio interface to record... In that scenario I imagine you do need the Sync device.

If HDX is PCIe, does that mean this Sync device only works on Windows workstations with PCIe ports, not Mac systems?

[devinemke]

Originally Posted by PhilipKapadia

You could demux audio from an SDI signal through a Blackmagic SDI to Analogue audio converter: https://www.blackmagicdesign.com/uk/...miniconverters

right...but the Dual SDI/HD/3G Card for the MTRX that I mentioned is the only device that I am aware of that is directly visible in the Pro Tools i/o. The card fits into the MTRX, which in turn connects to HDX via DigiLink, and thus is available as an i/o source in Pro Tools.

[BScout]

Originally Posted by PhilipKapadia

If HDX is PCIe, does that mean this Sync device only works on Windows workstations with PCIe ports, not Mac systems?

No. HDX and HDn cards work in particular models of Sonnet thunderbolt/PCIe chassis. Either that or the Mac Pro. Both are options to run those cards (and therefore SyncHD/SyncX) with Macs. I'd dare say that is most of the re-recording stages using Pro Tools at this point.