Issues with 44.1/16 playback on Sennheiser HDB 630 via USB (ref#U670BX)

[Alex_Lubberts]

What best describes your playback issue?

· Music doesn't start when I press "Play"

What type of Zone is affected by this problem?

· *Directly-connected Zones* are affected.

Does the issue affect all file formats?

· The issue affects *multiple/all* file formats.

Does the issue happen with local library music, streaming service music, or both?

· *Both streaming and local* *library* music are affected.

Do you encounter any playback errors with the "System Output" Zone?

· The System Output has *no problem*, it's only my other Zone.

How is the affected Zone connected to your RoonServer machine?

· Cable (USB, HDMI, SPDIF, etc.)

Is your device connected directly to the Roon Server via cable or over the network, or is it chained through another device (such as a streamer, Roon Bridge, or Roon Remote)?

· It is connected through a different device (e.g Rasberry Pi)

Does the device play audio from another source when using the same connection?

· The device has no problems with another audio source

Have you checked that Roon is whitelisted in any firewalls?

· I've checked the firewall and the issue remains

If the device has multiple output options, do the other options work as expected?

· Only one output type is affected while the other output type works as expected

Is the device using the latest firmware as per the manufacturer?

· Firmware is up-to-date but the issue remains

Do you have an approximate timestamp of when the issue last occurred?

· 21:45 CET; track: But not for me by Chet Baker

What are the make and model of the affected audio device(s) and the connection type?

· Sennheiser HDB 630 (via USB cable)

Describe the issue

When I connect my Sennheiser HDB 630 headphones with a USB cable to my Mac, or to a Pi with Ropieee playing tracks in 96/24 format works, but I get error notifications "Too many failures" when playing 44.1/16 format.

Converting sample rate to "Max PCM" works as a workaround.

Describe your network setup

My Roon core is connected with ethernet to my TP-link Deco, Ropieee is connected wirelessly to my Deco. But streaming to my Topping DAC from the same Ropieee works fine, so I don't suspect the network.

[vadim]

Hello @Alex_Lubberts

Thank you for reaching Roon support.

I think the next step here is to enable some diagnostics on your account so our technical staff can get some more insight into what’s going on here.

However, before I enable this feature, I’d like to ask for your help ensuring we gather the right information.

First, can you please reproduce the issue once more and note the time at which the error occurs. Then respond here with that time, and I’ll make sure we review the diagnostics related to that timestamp.

[Alex_Lubberts]

Thanks for looking into this.

It’s 15:44 CET and I tried a playlist with Queen songs. Roon skipped We will rock you, Under pressure, We are the champions, Somebody to love and then said: “Too many failures”.

I’m very curious what the logs say, but also have been thinking about this. When I plug the HDB 630 in my Mac and look at the Audio and MIDI settings, I see this:

There is only 16 bit support for 44.1kHz, and I think Roon is sending 44.1/24, because I have volume normalization enabled. Could this be the problem?

[benjamin]

Hey @Alex_Lubberts,

Yes - you’re exactly on the right track.

The behavior you’re describing strongly suggests a sample rate / bit depth mismatch between Roon’s output and what the Sennheiser HDB 630 can actually accept over USB.

You have a few options to consider for next steps:

Option 1: Match Roon’s output to the device

• In Device Setup → Advanced, set:
  • Max sample rate: 44.1 kHz
  • Max bits per sample: 16 bit
• Disable Volume Leveling (or use it but enable “DSP Engine → Convert to 16-bit”)

Option 2: Keep normalization but resample

• Leave Volume Leveling on, but in DSP → Sample Rate Conversion, set:
  • 44.1 kHz → 48 kHz or 96 kHz
  • Output bit depth: 24-bit
• This avoids the unsupported 44.1/24 mode.

Option 3: Use your Mac’s system output

• Since “System Output” works fine, Roon can pass through macOS’s Core Audio handling, which automatically manages format conversions.

[Alex_Lubberts]

I think I’ll go for option 2.

I’m a bit surprised though about this limitation of the HDB 630 which I find rather strange. That may be the root cause of this issue, though I do think Roon could handle this a bit better. Strange as this may be, the HDB 630 does report its capabilities correctly (see screenshot above), so Roon could handle this better.

Anyway, thanks for your support!