• Registered: 2024-06-01
  • Posts: 16

Topic: DigiFace USB setup only fully functioning at max. sample rate

I’m using a DigiFace USB as output device in my Dirac Live Bass Control setup (LR speakers and currently two subwoofers). The Dirac output channels are assigned to ADAT 1 (L), ADAT 2 (R), ADAT 3 (sub 1) and ADAT 4 (sub 2). DigiFace outputs 1 (ADAT1/2) and 2 (ADAT3/4) are configured as S/PDIF and connected to two stereo DACs.

Everything works as expected when the sample rate of the input signal is 192kHz. At any other sample rate the L+R channels work but the subwoofer channels are silent. This is despite the level meters in both Dirac and TotalMix showing signal on the subwoofer channels.

The DACs handling the L+R and the subwoofer outputs are identical devices, and I swapped them over to rule out a defect in one of them.

What could make output 2 (ADAT3/4) go silent at sample rates other than 192kHz?

  • vinark
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Re: DigiFace USB setup only fully functioning at max. sample rate

Open totalmix and see what happens with sample rate changes. The number of output pairs and probably the numbering changes from 4 pairs at 192khz to 16 pairs at 44. At 44 you should probably send the subs to output 9 and 10.

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

3 Reply by Steffen (edited by Steffen 2024-06-06 09:52:41)

  • Registered: 2024-06-01
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Re: DigiFace USB setup only fully functioning at max. sample rate

vinark wrote:

Open totalmix and see what happens with sample rate changes. The number of output pairs and probably the numbering changes from 4 pairs at 192khz to 16 pairs at 44. At 44 you should probably send the subs to output 9 and 10.

Brilliant, thanks. The number (and therefore numbering) of channels changes with sample rate. I should have paid attention to this table in the manual:

Single Speed
Digiface USB ADAT (1-8)
Digiface USB ADAT (9-16)
Digiface USB ADAT (17-24)
Digiface USB ADAT (25-32)

Double Speed
Digiface USB ADAT (1-4)
Digiface USB ADAT (5-8)
Digiface USB ADAT (9-12)
Digiface USB ADAT (13-16)

Quad Speed
Digiface USB ADAT (1+2)
Digiface USB ADAT (3+4)
Digiface USB ADAT (5+6)
Digiface USB ADAT (7+8)

I now have playback channels 3/4 (subwoofers) routed to hardware outputs 3/4 (Out 2 in quad speed), 5/6 (Out 2 in double speed) and 9/10 (Out 2 in single speed). Subwoofers work at all sample rates now.

This also means, if I understand this correctly, that I can only have a total of four (instead of six) subwoofers connected using stereo DACs, because Out 3 clashes with the channel numbers of Out 2 at double or quad speeds. Unless there is a way of changing the routing depending on sample rate, which I guess isn’t possible.

I suppose I can live with that, I wasn’t planning on using more than four subs anyway.

Thanks again!

  • vinark
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Re: DigiFace USB setup only fully functioning at max. sample rate

I am glad you grasped it this good! I don't think there is automatic scene changing in totalmix. Do you change sample rate that much that selecting a scene manually is a problem?

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

5 Reply by Kubrak (edited by Kubrak 2024-06-06 10:49:28)

  • Kubrak
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Re: DigiFace USB setup only fully functioning at max. sample rate

@Steffen,
you could have different routing snapshots for different sample rates in Total Mix.

And search this forum, there was quite recently a discussion, how to handle multichanel on DF USB while changing sample rate...

  • Registered: 2024-06-01
  • Posts: 16

Re: DigiFace USB setup only fully functioning at max. sample rate

vinark wrote:

Do you change sample rate that much that selecting a scene manually is a problem?

I’m using this for music playback. My source material has all kinds of sample rates and I would like to avoid resampling (beyond what the DACs do already) if possible.

7 Reply by Steffen (edited by Steffen 2024-06-06 11:46:16)

  • Registered: 2024-06-01
  • Posts: 16

Re: DigiFace USB setup only fully functioning at max. sample rate

Kubrak wrote:

@Steffen,
you could have different routing snapshots for different sample rates in Total Mix.

And search this forum, there was quite recently a discussion, how to handle multichanel on DF USB while changing sample rate...

If switching between snapshots could be automatic (based on sample rate) this would be great. Even if it could, it would likely be a TotalMix feature. I’d rather not depend on having TotalMix running at all times while playing music.

Thanks, I’ll search for the multi-channel discussion.

  • Kubrak
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Re: DigiFace USB setup only fully functioning at max. sample rate

TM runs all the time, anyway.

9 Reply by MC

  • MC
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Re: DigiFace USB setup only fully functioning at max. sample rate

Steffen wrote:

If switching between snapshots could be automatic (based on sample rate) this would be great.

That will not happen, sorry. Try to connect your gear more cleverly to the outputs, or

Kubrak wrote:

And search this forum, there was quite recently a discussion, how to handle multichanel on DF USB while changing sample rate...

look here:

https://forum.rme-audio.de/viewtopic.php?id=39296

Regards
Matthias Carstens
RME

MC's Website

  • Registered: 2024-06-01
  • Posts: 16

Re: DigiFace USB setup only fully functioning at max. sample rate

MC wrote:
Steffen wrote:

If switching between snapshots could be automatic (based on sample rate) this would be great.

That will not happen, sorry. Try to connect your gear more cleverly to the outputs, or

Kubrak wrote:

And search this forum, there was quite recently a discussion, how to handle multichanel on DF USB while changing sample rate...

look here:

https://forum.rme-audio.de/viewtopic.php?id=39296


Yes thanks, I found that thread. Same problem as mine, same solution. I can live with the loss of one S/PDIF output, so I’m happy.

The DigiFace setup has brought the timing of my L+R and subwoofer channels, that was all over the place and highly variable, to within a tight few microseconds.