Antelope 32 HD delay compensation issues [SOLVED]

[ZEUSS]

Originally Posted by BScout

All our interfaces are externally clocked. For all our systems. And we do not have problems at all.

We don't use loop sync at all (and if you use an external clock, you should not have the loop sync bnc connectors also connected; that confuses Pro Tools.)

You have to set external clock per device from the Session setup window. (Yes, stupid, but true. Flip through each device and then go back to whatever you want to signify as the "loop master" as the last device to set clocking even if you aren't using it as a "loop master.")

Interesting thing, on Avid interfaces' word clock and loop sync, it is unbuffered from in to out. With loop sync always working at Fs (vs 2Fs or 4Fs even if that is your session sample rate is a 2Fs or 4Fs rate.) Word clock input/output does stay at the actual Fs. However, the MTRX does not do this as it is not an actual true Avid interface. It is buffered. It also always operates on its internal clock -- only "referencing" external clock input if set to use word clock input. For that reason, all our systems with MTRX units use the MTRX as the master clock (referencing Pro Tools so it will follow the session sample rate) and one MTRX in a system will send its external WC to a WC distributor(s) that then sends to the other Avid or non-Avid hardware (including the SyncHD) in a star configuration.

Also make sure 75ohm termination is set up correctly depending on what the end points of your word clock chain are. For instance, the Sync HD is not terminated and a terminator should be placed on the WC out if you are sending a WC in from an external clock. You kind of have to go through all the hardware connected to find out what they do unless they are very clear about it (like RME is with the blue button/yellow led for termination.) And at worse, you put a T connector on a WC in and terminate the other side of the T.

First off, thanks for the very detailed explanation! I didn't even know that you could adjust the clocking with audio media setup! Protools can't be active or it won't show it. It was definitely set to something weird. I changed it to HD I|O #1 Internal. So that is fixed and set!

I also went through the list and selected WC for all the other interfaces and then ended with selecting the first unit (Red Line16) as "Loop Master" Exactly how it was before.

All termination is correct and I have it setup just like you do. Red sending clock to BB which distributes to the 3 other units. The BB has the termination port LED lights also indicating proper termination.

I have 4 very basic test sessions at 4 sample rates. 44.1/48,88.2/96K with a test tone output to the various interface and an audio file set to output to main outs.

I can easily start with 44.1 then shutdown the session. Then go to the 48K Session and open it. Then go back to 44.1 and it works. As soon as I go back to 48K protools swods and hangs but all the interfaces are clocked and locked. It will then stop swodding but then everything is unresponsive and I have to force quit and restart.Its something in the software somewhere. Maybe the driver?

I can't figure it out. There are times where I can open sessions with different rates 4 times in a row but beyond that it gets confused some how. I am on 10.12.6 Sierra. Could it be that? I have done all the trashing and other basic troubleshooting. Only other thing is to maybe move the order of the interfaces but I think the Red should be master in port 1. The last bit of info is I am only using the first DIGILINK out of the Red as I don't need the DANTE ins and outs. Any Ideas?