Hi,
Unfortunately this cannot be accomplished, as it is by-design,
Here only one device can be marked as default device, for more information follow these below steps.
- Click Start, type Sound in the Start Search box.
- Click Sound in the search results at the top of the Start menu.
- Click the Playback tab. Notice the check mark next to the default device.
As this is a by-design issue, there would be nothing much we can do from our end.
If you want to suggest change in the design here is the link you can refer to: Microsoft Connect - Product Feedback and Bug Reporting | Microsoft...
https://connect.microsoft.com/dashboard/info/
Thanks and Regards:
I. Suuresh Kumar- Microsoft Support.
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