[Solved] Windows audio output stutters, then VM hangs

[kevinyank]

VirtualBox version: 6.0.8 r130520
macOS version: 10.14.5

For the past couple of days I've been trying to get a Windows VM with working audio output without much luck. I'm using Microsoft's IE Testing VM downloads and importing them into VirtualBox, but no matter what I try I find the audio stutters and then pretty soon causes my VM to hang.

I have tried the Windows 7 IE11 image, which initially starts up without an audio driver, but running Windows Update causes it to find and install the AC97 audio device driver. After doing that, if I drag the system volume slider up and down a bit and release it I'll hear the system volume chime play in a stuttery way each time. After a handful of these chimes, the VM freezes.

Thinking the problem might be with Windows 7, I tried downloading the Windows 8.1 IE 11 image. It too lacked an audio driver for the AC97 device out of the box, and this time Windows Update was no help. I managed to find a third-party download for this driver, installed it, and found the same behaviour: audio playback is initially stuttery, then soon results in a VM freeze.

Thinking the problem might be with the AC97 support, I switched my Windows 8.1 IE11 VM to use Intel HD Audio. Windows recognised this device and updated its driver when I prompted it to, but testing the audio playback produced identical results: audio playback is initially stuttery, then soon results in a VM freeze.

I've attached a VM log for the Windows 8.1 guest running with Intel HD Audio from cold boot through to freeze and force quit.

[socratis]

00:00:01.613520 VRDP: TCP server listening on port 5958 (IPv4).

Disable the VRDP server.

00:00:01.663323 NumCPUs <integer> = 0x0000000000000001 (1)
00:00:01.853292 CPUM: Physical host cores: 6

Give your VM a 2nd CPU, it's going to be running much smoother.

00:00:01.663490 3DEnabled        <integer> = 0x0000000000000000 (0)
00:00:02.366590 GUI: 2D video acceleration is disabled

Shut down the VM. Go to the VM Settings » Display » Screen. Enable 2D and 3D acceleration. Increase the VRAM to the max 256 MB.

00:00:01.851967 Audio: Found 8 devices for driver 'CoreAudio'

How about simplifying your audio setup, when you are having audio problems? It makes sense, doesn't it? Keep the basics!

00:00:01.852037 Audio: Device 'Soundflower (64ch)':

Completely uninstall SoundFlower, it's 1) a known troublemaker, 2) not maintained, abandonware since 5 years ago, way before 10.14.5 was out. See https://github.com/mattingalls/Soundflower

00:00:01.851990 Audio: Device 'Boom2Device':

Uninstall it.

00:00:01.852052 Audio: Device 'ZoomAudioDevice':

Uninstall it.

00:00:01.852066 Audio: Device 'DisplayPort':

Disconnect it.

00:00:01.852081 Audio: Device 'External Headphones':

Disconnect them.

At the end of the day, what I want to see in your VBox.log is:

00:00:05.238126 Audio: Found 2 devices for driver 'CoreAudio'
00:00:05.238142 Audio: Device 'Built-in Microphone':
00:00:05.238146 Audio: 	Usage           = Input
00:00:05.238149 Audio: 	Flags           = DEFAULT
00:00:05.238152 Audio: 	Input channels  = 2
00:00:05.238156 Audio: 	Output channels = 0
00:00:05.238159 Audio: Device 'Built-in Output':
00:00:05.238162 Audio: 	Usage           = Output
00:00:05.238165 Audio: 	Flags           = DEFAULT
00:00:05.238168 Audio: 	Input channels  = 0
00:00:05.238171 Audio: 	Output channels = 2

[kevinyank]

Thank you! This advice solved the problem perfectly.

The increased hardware specs certainly made my VM run much more smoothly. It's a wonder these aren't the default settings when a Windows 8.1 guest is detected at import!

I also wasn't aware I had so many crusty, old audio devices hanging around. Getting rid of Boom and SoundFlower has gotten rid of the hangs. ZoomAudioDevice seems not to be causing problems, which is lucky because I need the Zoom software for my work.

Thanks again!

[socratis]

No problem, glad you got it going. Marking as [Solved].