VBox, Win7 guest, Debian host, audio input not working at boot 99% of the time

Question

People have been complaining about audio issues with virtualbox for ages. Crackling sound and similar audio output issues can generally be linked to the problem of having a precise clock despite a virtualized environment.

My issue is different. I have a setup where the output is working very decently, but not the input. I need a Windows VM to run corporate apps such as Skype. My USB headset is managed by the Linux host and the Windows guest just sees generic audio input and output. I've been struggling for a long time with joining audio conferences, hearing and not being heard.

To make it worse, it sometimes work after rebooting, something like 1 in 100.

I have tried many things, such as modifying the emulated hardware, changing the audio host type, and so on. Results were at best on par, sometimes worse. A partial solution is the USB passthrough of the headset, but I then lose the headset on the host, and I get crackling output, with working, low quality (as reported by listeners) input.

What can I try next?

Answer 1

User teobaldo suggested an approach which finally nailed it for me:

try to restart "Audiosrv" service on Windows x64 and sound should return

After a lot of fiddling, I have a reproducible way of fixing this issue:

1. in guest, run services.msc, accept UAC, stop Windows audio service
2. in host, disable VM audio input (eg right click on the status bar)
3. in host, enable VM audio input
4. in guest, start Windows audio

The order above matters, believe me.

All in all, it looks like there is some timing issue between the guest and Vbox, which sometimes works but most of the time doesn't, in my case. YMMV. By taking the steps manually, I guess I am doing things properly, so that it just works (TM).

Hope this helps!