Can't capture system sound on iMac Pro

iMac Pro, macOS 10.13.3

I've tried capturing System Sound / Computer Audio using SiennaTV NDI Scan Convertor, Telestream ScreenFlow, Telestream Wirecast Screen Capture except when using USB Audio Out?

When System Preferences Sound Output is set to iMac Pro Speakers or External Headphones on the Headphone Port I can't capture sound but, oddly when I set it to USB Audio Output I can capture System Sound.

The only correlate I see is in Apple Audio MIDI Setup iMac Pro Speakers and External Headphones are 32 Bit Float and can't be changed unlike other Macs I've used. On the other hand USB Audio Output is 16 Bit Integer.

Anyone seeing this in other screen capture utilities?
Any screen capture utilities able to capture computer audio?

I can only capture system sound / computer audio when this is set to my Output.

iMac Pro (2017), macOS High Sierra (10.13.3), 8 Core, 32GB RAM, GPU Vega64

Posted on Jan 28, 2018 7:17 PM

Similar questions

18 replies

Mar 6, 2018 7:36 PM in response to Craig Seeman

Thanks Craig, found a stop gap for now, hopefully we get a better resolution soon.

Craig Seeman Author

Level 4

2,137 points

Feb 15, 2018 6:26 PM in response to MaineMac

I bought a Berhinger U-Phoria UMC22 which can take a mic in and has headphones and speaker output jacks.
Then I was able to capture system sound.

I've since found out that the iMac Pro has a processor to handle sound that doesn't exist in previous Macs. As a result the companies that make software that previously captured system sound through a audio driver will have to rewrite the audio capture portions of their program.

Kinda surprised that in nearly three weeks you've been the ONLY one to respond.

MaineMac

Level 1

4 points

Feb 15, 2018 7:32 PM in response to Craig Seeman

Excellent point about the iMac Pro’s unique processor. I have sent that comment along to TechSmith’s support people and asked if they were aware of this and whether they planned to issue a new driver. Will advise of their response.

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Can't capture system sound on iMac Pro