BMD Decklink 4k audio problem

Good Morning to all.
First I would like to thank everyone who has helped me get this far without even knowing they were.

My current problem is with a BMD decklink extreme 4K 12G card.
I have a system built in the following config.
Dell Xeon (x 1) tower with 16 GB ram, win 10 boot drive and 2 drive raid media drive.
2 x extreme 4K 12g are used as playout cards (fill/key).
BMD drivers in use are 11.7.
Caspar version is 2.3.3 lts stable.

When playing out a video (animation in SD) with embedded audio using caspar client 2.2, the embedded audio shows output on the audio meter, plays embedded audio in the sdi signal (through a BMD multiviewer 4k on HDMI port) but there is no output on the analog balanced XLR connectors.
I have tested this layout using the extreme 3d+ cards to replace the 4K cards and everything works as expected.
I have looked through the BMD desktop utility and cannot see any switch to enable the xlr output.
Does anyone using the 4K card have any similar problem or better yet, a fix for this.


Do you get audio on the XLR’s when you play something with Media Express?

I have played out a sound file from Media Express with no audio on XLR feeds.
I will be back at the 4K systems on Thursday where I will run a full grab test using Media Express in and out to see what happens.

Afternoon all.
Here is an update on further testing preformed on the decklink extreme 4K 12G cards.
I have been in connect with BMD support regarding the audio issue above. They asked me to flash the 4K cards to see if this reset them. Both 4K cards, when connected to the usb port (external), were in need of an update according to the BMD drivers (11.7). This was completed successfully but there was still no audio on the xlr ports.

In keeping with BMD requests, I grabbed a video with audio using the decklink 3d+ card and media express. The source was a SD sdi signal with balanced analog audio from my current non BMD system. This recorded without problem and now I have a known good media express file. Playing it out on the 3D produces audio on the xlr.
When the file is transferred to the 4K card, the video plays but again no audio on the xlr (using media express). At this point, I removed the two 4K cards and replaced them with the two 3D cards. Interestingly, the 3D cards are no longer playing out audio on the xlr ports from the win 10 system.

The system differences are:
The 3d cards are in a me built i5 with win 7 using bmd ver 11.7. This config only allows for SD due to pci lane issues but that’s all i need for now. This works with media express.

The 4K cards are in a pre built new Dell 7920 tower with Xeon cpu on Win10 using bmd ver 11.7. This does not work with 4K cards (again in SD) and now seems to also close the xlr port on the previously working 3D card.
Sidenote: I did try the 4K card in the win 7 system but still don’t get audio.

I don’t think think this is a casparcg issue but these cards are being used here so any issues like this should have surfaced by now.

So questions:
Are there any know installation issues which win10 throws up with BMD cards ?
Are there any settings needed to change in win10 ?
Does anyone using the decklink 4K extreme 12G have a fully working rig ie sound out on xlr?

Any ideas would be welcome.


Does audio work with just one 4K card installed? I’m wondering if this is something related to them also being common sound devices in Windows.

Anyways the BMD forum seems to have plenty of people with similar issues with these cards.

Also are you using the same breakout cables for the 3 and 4’s? Perhaps the pinout is different between them.

I can’t remember if I tried a single card so I plan to try that tomorrow.
I did try the 4K breakout cable on the 3d card and it did work fine.
Apparently the cable is the same according to a previous mail I sent to BMD.
I have been through the BMD forum and have found no answers there.

Also test going into Device Manager and disabling the BMD Audio drivers for the cards under “Sound, video and game controlelrs”


quick update re problem. I now have 2 x 4k cards working with audio out of xlr but frankly am trying to find why they work. It may be a combination of bmd 12.2.2 driver and installing in a system with different version of win 10. (win10 pro verses win 10 pro for workstation). The new problem is I tried to recreate the working solution with the next two set of cards and it didn’t work for them.

Does anyone know if DaVinci Resolve 17 has any decklink cards built within it? (This is on the win10 pro system and I want to include or dismiss it as a possible solution).

Also has anyone upgraded to win 11 using extreme 4K cards and caspar?


Shortform answer: Yes - DaVinci Resolve 17 can capture video from an SDI source.

More details:
I’ve just checked on the capabilities reported by version 17.4.6 (free) on a Windows 10 machine with a Thunderbolt connected UltraStudio 4k.

You select the Capture and monitor devices in the Preferences->Video and Audio I/O page. DaVinci lists the detected capture devices in a drop down selector box. There is also a tick-box that releases the video interface if DaVinci is not the focussed app. Changes in the preferences are only activated when DaVinci restarts.

Capturing video is done via the “Media” operational mode. The capture tool is available in the top right corner, and is designed for capture from a VTR or Blackmagic Telecine device, but this tool includes the “Capture Now” mode used for live input. The video capture properties are entered via the project properties->Capture and playback form. Settings include scan rate, the SDI link mode (single, dual,quad) data levels (video or full), bits/sample, capture with/without audio, wrapper (Quicktime or DPX), codec (DNxHD or uncompressed), number of audio channels.

There are no options for setting the audio source (embedded assumed), but in a Blackmagic Forum post about capture from a webcam (item) Dwaine Maggart notes that the video source should be switchable to, for example, HDMI using the Desktop Video GUI. The source select buttons on the front of my Ultrastudio do change the signal visible in Resolve, so hopefully the GUI can also change video and audio selections for PCIe connected cards. Not sure if these settings would be non-volatile.

I suspect the capture scan rate options change depending on the chosen Decklink card. DaVinci is offering capture resolutions up to UHD 2160p60 on my Ultrastudio (this is also the maximum output resolution limit for the free version).