Topic: 12mic sample rates

I'm trying 12mic out with a Fireface UFX+, connection over MADI coax.

Just a quick question about clocking - I have the UFX as the master, and the 12mic clocked over MADI, very simple. When I change sample rates, for example, open a 48k Pro Tools session after a 44.1 session, the 12mic doesn't follow. It flashes its red front panel light at me, and I have to use the browser remote to manually change the sample rate, at which point everything goes green again.

I would have expected the 12mic to change itself... Is this correct behaviour?

Re: 12mic sample rates

Have you checked the Fireface settings during opening of the protools project ?
Does the protools project change the samplerate in the settings window ?
It has to.
Protools is not a clock.
The used sample rate setting inside of the project must be obtained to the UFX first and the Fireface settings window is where you can see if this happens.

M1-Monterey, Madiface Pro, Digiface USB, Babyface silver

3 (edited by ramses 2021-04-01 12:44:42)

Re: 12mic sample rates

Camilo1 wrote:

I'm trying 12mic out with a Fireface UFX+, connection over MADI coax.

Just a quick question about clocking - I have the UFX as the master, and the 12mic clocked over MADI, very simple. When I change sample rates, for example, open a 48k Pro Tools session after a 44.1 session, the 12mic doesn't follow. It flashes its red front panel light at me, and I have to use the browser remote to manually change the sample rate, at which point everything goes green again.

I would have expected the 12mic to change itself... Is this correct behaviour?

Reason for this is explained here:

https://www.forum.rme-audio.de/viewtopic.php?id=20724

> [..] there is no clock information that tells the unit in which SMUX mode it is. No SMUX, SMUX2, SMUX4 [..]

BR Ramses
UFX+, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1650v4, Win10Pro22H2, Cub12Pro

Re: 12mic sample rates

Also it is not possible to implement SMUX. It would go wrong when the 12Mic is used in a AVB Network and would be slave to the MADI connection.

Regards,
Audio AG Support

Re: 12mic sample rates

I'm not quite understanding this it seems.. I'm not talking about higher sample rates, it's just 44.1 to 48, and back again. Obviously the 12mic is quite aware that it's not running at the same sample rate as the UFX, but it waits for me to change it manually, rather than just slaving to it automatically like every other piece of ADAT, or Spdif, Word Clocked piece of equipment normally would.

Is this normal?

6 (edited by ramses 2021-04-01 16:51:36)

Re: 12mic sample rates

I have this MADI chain: UFX+----XTC-----12Mic
Clock Master: UFX+
Clock Slave: XTC and 12Mic (getting clock from MADI)

Same here, when switching UFX+ from 44.1 to 48 kHz (both single speed), then the XTC learns 48 kHz properly,
strangely the 12Mic doesn't learn the 48 kHz.

12Mic Firmware:  fw_xm_1.3.0_v69 12mic 20201208-09H09M (v69)
XTC: 26/47
UFX+: v45
MADIface driver: 0.9734

BR Ramses
UFX+, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1650v4, Win10Pro22H2, Cub12Pro

Re: 12mic sample rates

This is due to AVB stream formats and described in the manual. The reason that the device shows a warning is that the entire AVB configuration would have to follow MADI or Word Clock input rate changes, causing stream disconnects, stream configuration, and reconnects. This in turn would then cause all other devices that synchronize to this stream to throw errors.

That means that the user of a MADI device would have the ability to reconfigure an entire AVB network unknowingly/unintentionally, and the error would only show at the devices that are connected to the 12Mic, not at the 12Mic itself. So we decided that in a network, it is better to make these changes intentionally at the earliest point possible and show the divergence at the first unit that receives the MADI signal. Therefore, the 12Mic shows an error if the sampling rate is different from the one that was set.

Best regards,
Max

Re: 12mic sample rates

Max wrote:

This is due to AVB stream formats and described in the manual. The reason that the device shows a warning is that the entire AVB configuration would have to follow MADI or Word Clock input rate changes, causing stream disconnects, stream configuration, and reconnects. This in turn would then cause all other devices that synchronize to this stream to throw errors.

That means that the user of a MADI device would have the ability to reconfigure an entire AVB network unknowingly/unintentionally, and the error would only show at the devices that are connected to the 12Mic, not at the 12Mic itself. So we decided that in a network, it is better to make these changes intentionally at the earliest point possible and show the divergence at the first unit that receives the MADI signal. Therefore, the 12Mic shows an error if the sampling rate is different from the one that was set.

Best regards,
Max

Great, thank you Max, that makes a lot of sense.

So, in the following scenario, does the 12mic change sample rate or not?

UFX+: 44.1khz, master
12mic: 48khz, slave (connected with MADI coax)

The manual says the "resulting sample rate" will be "44.1khz with warning". Does this mean the 12mic has switched to 44.1khz, but it's not passing that information onto the AVB network? Or is the AVB stream in fact still be happily operating at 48khz?! Clearly I'm still stuck in 2001 with my understanding of clocking!!

Re: 12mic sample rates

The former. It has changed to 44.1, and the word clock outputs are 44.1, following the clock of the incoming MADI signal, but warns you that the entire AVB entity still presents itself as a 48k device.

Re: 12mic sample rates

Max, just a few thoughts on this topic.

I think there are many customers who buy the new devices to get the "latest and greatest" with an option for AVB in the future, but still have MADI and not concrete plans for switching to AVB.

Wouldn't it be possible to make the behaviour of AVB devices configurable, to either stay on a clock in favour of AVB (like it is now) or to follow the MADI clock ? I think there are enough customers still recording in single speed, then this would support the most used sample rates for audio and video: 44.1 and 48 kHz.

Not sure, but perhaps it could even be detected automatically, whether an AVB stream is active or not, as you need network addresses for sender and receiver, maybe even that would not be too hard.

Or are there still 1-2 MADI bits free for a RME unique solution to tell the MAID devices on a bus, whether single, double or quad speed is in use? Even 1 bit would make it possible to differentiate between single and double speed which is already a very nice range of 44.1 - 96 kHz (assuming only very few ppl use 192 kHz).

BR Ramses
UFX+, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1650v4, Win10Pro22H2, Cub12Pro

11

Re: 12mic sample rates

Hi Ramses,

there are several possibilities, each with different trade-offs and consequences. We have added the request to our feature request list and will update this post when we find the time to address this. For now let me just state once again that nothing is broken - the device syncs correctly to 44.1 or 48 kHz, regardless of the setting, if MADI or Word Clock is selected as clock source. The current sampling rate is detected and shown on the device and the user can easily see what causes the warning, and also change the sampling rate to clear the warning. This does not have any effect on audio or routing.

-Max