Hi Bill,
I would suggest you to refer to the following article and follow the steps given. It has steps to make the Jambox as
the default device to play music.
Jawbone BIG JAMBOX Wireless Bluetooth Speaker shows as "Offline" on Windows 8
http://support.microsoft.com/kb/2787646/en-us
Note: This also apploes to Windows 8.1.
Do get back to us with the status of the issue, so that we could help you further.