[SOLVED] Weird audio pass through problem

[promoxer]

# Main problem

There is a 2 seconds gap of silence after every 10 seconds of normal playback

# Setup

1. Proxmox 7.4-3
2. Passing through GPU + a PCIe Sound Blaster to Windows 10 VM
3. Running VAC https://vac.muzychenko.net/en/, same thing happens with https://vb-audio.com/Cable/index.htm (virtual cables)

# Findings

4. Playing audio in VM without the virtual cables works properly, the sound plays at the correct speed without any crackling
5. 1st clip is playing audio through VAC and shows the spectrum analyzer which matches with what I'm hearing, you can see the spectrum analyzer go silent for 2 seconds before returning while the video continues
6. The audio doesn't appear to be out of sync with the video, so I think VAC is dropping audio to catch up
7. 2nd clips shows a possibly related problem, Windows sound test clip is only 2 seconds, but animation takes 8 seconds

https://imgur.com/a/JMG95dD

Any idea what my problem might be? Thank you.

 

[psyyo]

4. Playing audio in VM without the virtual cables works properly, the sound plays at the correct speed without any crackling

Ok so your problem clearly has nothing to do with Proxmox.. It's in your virtual audio cable setup.

I personally use VB Audio's VoiceMeeter in a windows VM absolutely fine. It's essentially a bunch of virtual cables behind a mixer GUI.

Assuming your audio drivers are installed correctly i imagine what you're encountering is the sound engine unable to keep up with the data stream you're expecting of it. So it drops out, fills buffer again, and plays as long as possible ..

Try switching audio device from mme / ks / wdm, increasing buffer size, maybe even drop your audio to plain 16bit 44khz just for testing sake.

 

[promoxer]

I have been running this whole VB VAC DSP setup for years on bare metal and I do use VoiceMeeter as well athough mainly for it's VBAN abilities.

Let me try and see if I can route default sound into a Winamp DSP using VoiceMeeter. But VB cable had the same issue too, so I suspect it will be the same outcome with VoiceMeeter.

Can I ask, how do I switch mme/ks/wdm? and increase buffer?

Do you mean Windows? On the virtual cables side, I tried almost everything there is.

Thank you.

 

[promoxer]

I found the cause of my problem, it was the app that loads the DSP. It was fixed by updating it to the latest version.