1 Topic by benjaminfrog (edited by benjaminfrog 2022-08-29 02:51:50)

  • Registered: 2011-06-03
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Topic: UFX 20 Samples Behind UFX II When Synced

I've got the word clock out of my UFX II connected to the word clock in of my UFX, with the clock source of the UFX set to Word. I've also got the ADAT 1 out of my UFX going to the ADAT 1 in of my UFX II. Everything seems to be connected correctly and working as I'd expect, except that mics connected to the UFX are being recoding in my DAW about 20 samples later than mics connected to the UFX II.

I've got a matched pair of SDC mics lined up side by side on my desk, one connected to each interface. Recording the same source, it doesn't matter which mic is plugged into which interface, whichever one is plugged into the UFX is always about 20 samples behind the one plugged into the UFX II. Is this normal?

This is my first time connecting two interfaces. Being digital, it's easy to line up the waveforms after the fact, but I would have thought they'd be perfectly in sync. Any insight would be greatly appreciated. Thanks!

2 Reply by MC

  • MC
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Re: UFX 20 Samples Behind UFX II When Synced

The UFX II is connected to USB, the UFX operates stand-alone? Which sample rate is used?

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Matthias Carstens
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  • Registered: 2011-06-03
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Re: UFX 20 Samples Behind UFX II When Synced

I've tried it with the USB connected and with it disconnected and gotten the same result both ways. I usually use 48k, but I've tried 44.1 as well. Same result both ways.

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Re: UFX 20 Samples Behind UFX II When Synced

Sorry if my last response was unclear. The UFX II is always connected to USB. I've tried it with the UFX connected to USB and with it disconnected. It didn't seem to make a difference.

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Re: UFX 20 Samples Behind UFX II When Synced

Just tried it with the clock being sent over ADAT and am still getting the delay.

  • vinark
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Re: UFX 20 Samples Behind UFX II When Synced

I do not know the cause for sure, can be a number of things, different converter delay and added delay because of onboard mixer (has to go through the mixer to go to adat out), but whatever the reason, it is always advisable to record a stereo pair on the same converter(s), different converters have different process times and most are not in whole sample numbers, so a converter can have a delay of 5.3 samples and another of 8.7, which will be impossible to align perfectly (whether that is audible depends on the material and the mic placement).

Vincent, Amsterdam
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7 Reply by benjaminfrog (edited by benjaminfrog 2022-08-29 16:25:26)

  • Registered: 2011-06-03
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Re: UFX 20 Samples Behind UFX II When Synced

Thanks, Vincent. I wouldn't be splitting them between the two interfaces in a real-world recording, I just did that for testing purposes. Am I understanding correctly then that some delay would be expected and is normal?

  • vinark
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Re: UFX 20 Samples Behind UFX II When Synced

benjaminfrog wrote:

Thanks, Vincent. I wouldn't be splitting them between the two interfaces in a real-world recording, I just did that for testing purposes. Am I understanding correctly then that some delay would be expected and is normal?

To me yes, but only RME can say for sure what the exact number should be.
If the interfaces  would use the same driver (and they don't) both would show up together in your daw and you would not have to use adat to stream from one to the other.
So 2 ufx or 2 ufx2 would work like that (and also other combos like an ufx and a ucx(1 or 2) or an ufx2 and a ufx+).

Vincent, Amsterdam
https://soundcloud.com/thesecretworld
BFpro fs, 2X HDSP9652 ADI-8AE, 2X HDSP9632

9 Reply by ramses (edited by ramses 2022-08-30 07:04:45)

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Re: UFX 20 Samples Behind UFX II When Synced

You could check manuals, chapter Latency and monitoring, there you see the differences between AD/DA converter latency.
@48 kHz: UFX 12/28 samples AD/DA, UFX II 13/7 samples AD/DA.

Connecting both interfaces via USB makes no sense because they do not have the same ASIO driver.
Then your DAW can't access them both at the same time.
And if you do so, you need to take care manually in both ASIO drivers to use the same ASIO buffer size.

So, you need to connect the UFX II via USB to computer and UFX through ADAT to the main interface.

Latency compensation in the DAW you have only for analog ports on the main interface (UFX II), not for other hardware connected through ADAT.

If I remember right, the transfer through the internal digital matrix of the UFX and over ADAT is really fast with very low latency. But you will always get:
— 12 samples offset (@48 kHz sample rate) from the A/D conversion at the UFX. And this isn't known by the ASIO driver of the main interface. Maybe your DAW has a possibility to set an offset for this particular track.

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub13
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Re: UFX 20 Samples Behind UFX II When Synced

Thanks, Ramses. I appreciate the detailed response.

I have had the UFX II connected via USB to the computer and the UFX through ADAT to the main interface. When I've had the UFX connected via USB, it's been to configure the routing and enable/disable phantom power in TotalMix FX. It hasn't been because I was trying to record directly out of it. I've only been recording out of the UFX II.

That's an interesting idea about trying to configure a manual offset in my DAW. I'm not sure whether it's capable of that (it calculates delay compensation automatically), but I'll take a look at the manual. Thanks for the suggestion.

11 Reply by ramses (edited by ramses 2022-08-30 14:18:42)

  • ramses
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Re: UFX 20 Samples Behind UFX II When Synced

As a side note, keep the 2nd ASIO driver for the UFX installed, even if you use it in “kind of” stand-alone mode connected through ADAT (regarding audio transfers).

Then you can still operate your UFX (through USB in terms of driver settings and TM FX).

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub13
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Re: UFX 20 Samples Behind UFX II When Synced

Yes, that's what I've been doing.