MTRX Sync Dante and Video

[laki]

Hi All,

I've got a few MTRX units. At the moment I am feeding them Video Ref from the pass through on the Sync HD. The thinking being that everything is resolved to the same clock.

We are using Dante Virtual Soundcard to listen the Mac audio.

However, Dante seems to have an issue keeping sync. The Mac audio will drop out. The only way to get it back is to toggle external clock in Dante Controller. My thinking is that since the Mac has no ref input, the only way to keep everything digitally synchronized is to use Dante IP as the Sync source in the Dadman software.

I've done a few tests with laybacks both ways and Sync is rock solid.

The SyncHD is still using House Sync reference. The SyncHD is controlling the sync of the Timeline to the external deck while Dante is acting as the digital clock master. The Video Deck is using House Sync as reference however digital sync is coming via it's input. In this case AES that has been converted to SDI.

Does anyone foresee a problem with this? Or a better way of going about this?

[dr sound]

Here's what I do and it's ROCK SOLID:
Get this:
http://www.brainstormtime.com/dcd12.php
Feed all the Pro Tools Word Clock
Feed the MTRX Word Clock.
Every thing smooth, no issues and sounds great,
Is your Video Reference Tri Level Sync?
If it is you can feed it into The Brainstorm as "reference in" and it
will then create word clock and that is fed to all pro Tools systems and
the MTRX .

[MIKEROPHONICS]

I think the macs can’t keep constant sync with no sync ref input. When monitoring the mac digital op for soundminer/internet etc I use SRC on my Omni digital inputs which reclocks whatever nonsense the mac ops.
I can’t help feeling your solution above is driven the wrong way around.
Marti’s suggestion seems very elegant.
What video peripheral do you use?
Marti do you reference your AJA from the video that feeds the wordclock DA?
If so, can the Sync HD be locked to wordclock whilst the AJA is locked to video?
Just trying to understand (and learn) as this is a new approach for me and due to my lack of outboard gear (apart from mic amp and vid ref gen/Sync HD) I am unable to test this


Sent from my iPhone using Tapatalk

[Frank Kruse]

Originally Posted by laki

Hi All,

I've got a few MTRX units. At the moment I am feeding them Video Ref from the pass through on the Sync HD. The thinking being that everything is resolved to the same clock.

We are using Dante Virtual Soundcard to listen the Mac audio.

However, Dante seems to have an issue keeping sync. The Mac audio will drop out. The only way to get it back is to toggle external clock in Dante Controller. My thinking is that since the Mac has no ref input, the only way to keep everything digitally synchronized is to use Dante IP as the Sync source in the Dadman software.

I've done a few tests with laybacks both ways and Sync is rock solid.

The SyncHD is still using House Sync reference. The SyncHD is controlling the sync of the Timeline to the external deck while Dante is acting as the digital clock master. The Video Deck is using House Sync as reference however digital sync is coming via it's input. In this case AES that has been converted to SDI.

Does anyone foresee a problem with this? Or a better way of going about this?

I do a similar thing:

PT audio goes out AES to a Xilica Neutrino processor and mac audio coming into the same box via DVS. A have seen the mac dropping out of sync in the Dante Controller where the sync light comes on and off but only as a very occasional glitch and back in the days where I didn't have the QoS settings (see here https://www.audinate.com/resources/networks-switches) in my SG300 set correctly. Dante sync is kind of self-negotiated (there can only be one master that you can set AFAIK for the Dante network) so I doubt is has something to do with the house sync distribution. My guess would be a network problem. There is no actual "physical" clock signal in Dante. It's packet based audio.

Which device is your "preferred master" in the Dante controller?


From the Dante FAQ https://www.audinate.com/resources/faqs

I have an unstable device clock on my Dante network - why is this?
There are a range of network conditions that can interfere with a device’s clock stability. These include:

A switch on the network is configured to use Energy Efficient Ethernet ('Green Ethernet') functionality
A 100 Mb switch or link is present where a Gigabit connection is required
One or more switches are incorrectly configured
A 'problematic' external word clock is being used as the master clock
Clock instability is often a result of overloaded network links. As a rule of thumb, total bandwidth utilisation (including multicast and unicast) on any given link should not exceed 70% of the supported bandwidth for that link. Utilisation above 70% of supported bandwidth can adversely impact clock synchronization (especially if there is also non-Dante traffic on the network).

[ntp-jl]

Hi Laki,

If I understand it correctly, you have set sync source in DADman to IP. In that case, the MTRX will not sync to the video ref, hence it will not be sync'ed to the house clock. Instead you must set the sync source to Video.

The Dante clock is in that case automatically sync'ed to the video ref through the MTRX as the Dante interface in the MTRX is forced to external clock.

That should hopefully solve your issue, otherwise please let me know.

[laki]

Originally Posted by dr sound

Here's what I do and it's ROCK SOLID:
Get this:
http://www.brainstormtime.com/dcd12.php
Feed all the Pro Tools Word Clock
Feed the MTRX Word Clock.
Every thing smooth, no issues and sounds great,
Is your Video Reference Tri Level Sync?
If it is you can feed it into The Brainstorm as "reference in" and it
will then create word clock and that is fed to all pro Tools systems and
the MTRX .

Thanks Marti. This is truly a nice solution and makes sense.

Not using Tri Level Sync at the moment.

[laki]

Originally Posted by MIKEROPHONICS

I think the macs can’t keep constant sync with no sync ref input. When monitoring the mac digital op for soundminer/internet etc I use SRC on my Omni digital inputs which reclocks whatever nonsense the mac ops.
I can’t help feeling your solution above is driven the wrong way around.
Marti’s suggestion seems very elegant.
What video peripheral do you use?
Marti do you reference your AJA from the video that feeds the wordclock DA?
If so, can the Sync HD be locked to wordclock whilst the AJA is locked to video?
Just trying to understand (and learn) as this is a new approach for me and due to my lack of outboard gear (apart from mic amp and vid ref gen/Sync HD) I am unable to test this


Sent from my iPhone using Tapatalk

Hi Mike, thanks for your response. I'm using a Black Magic Decklink 4k Studio. I was feeding ref to the BM from the SyncHD but have since sent it to the MTRX instead.

Our original setup was Word Clock out of the SyncHD into the MTRX but unfortunately, as soon as you quit PT, SyncHD stops sending WC so the MTRX has no sync.

Marti's WC master is a good way to keep the WC flowing all the time.

[laki]

Originally Posted by Frank Kruse

I do a similar thing:

PT audio goes out AES to a Xilica Neutrino processor and mac audio coming into the same box via DVS. A have seen the mac dropping out of sync in the Dante Controller where the sync light comes on and off but only as a very occasional glitch and back in the days where I didn't have the QoS settings (see here https://www.audinate.com/resources/networks-switches) in my SG300 set correctly. Dante sync is kind of self-negotiated (there can only be one master that you can set AFAIK for the Dante network) so I doubt is has something to do with the house sync distribution. My guess would be a network problem. There is no actual "physical" clock signal in Dante. It's packet based audio.

Which device is your "preferred master" in the Dante controller?


From the Dante FAQ https://www.audinate.com/resources/faqs

I have an unstable device clock on my Dante network - why is this?
There are a range of network conditions that can interfere with a device’s clock stability. These include:

A switch on the network is configured to use Energy Efficient Ethernet ('Green Ethernet') functionality
A 100 Mb switch or link is present where a Gigabit connection is required
One or more switches are incorrectly configured
A 'problematic' external word clock is being used as the master clock
Clock instability is often a result of overloaded network links. As a rule of thumb, total bandwidth utilisation (including multicast and unicast) on any given link should not exceed 70% of the supported bandwidth for that link. Utilisation above 70% of supported bandwidth can adversely impact clock synchronization (especially if there is also non-Dante traffic on the network).

Thanks Frank. Im not using a preferred master at the moment. Just using the election process.

When I get a moment I will check the QOS settings. The switch is definitely not EEE!

[laki]

Originally Posted by ntp-jl

Hi Laki,

If I understand it correctly, you have set sync source in DADman to IP. In that case, the MTRX will not sync to the video ref, hence it will not be sync'ed to the house clock. Instead you must set the sync source to Video.

The Dante clock is in that case automatically sync'ed to the video ref through the MTRX as the Dante interface in the MTRX is forced to external clock.

That should hopefully solve your issue, otherwise please let me know.

Thanks for your reply. I have set the sync source to Video. However, when I do this, sometimes the Dante connection from my Mac's Dante Virtual Soundcard, goes mute. The only way to get it back is to toggle the external clock setting in Dante Controller.

I must either have an unstable video reference or the network is not set up properly.

[ntp-jl]

Next time the DVS mutes, please go to Dante Controller and check the latency measurements for the DVS. This will most likely show that samples arrive too late. If that is the case, it is most likely because multicast is disabled in your network. If that is the case, make sure it is enabled, preferably just by using IGMP.