Right-click on the white speaker icon located in the system tray on the Windows task bar near the clock.
Choose Playback Devices
Select the audio device that you would like to adjust (i.e. - AudioBox, FireStudio)
Choose the Advanced tab
Uncheck the Allow applications to take exclusive control of this device box (both boxes will be disabled now)
Repeat these steps for any additional devices on the Playback tab (e.g. - the AudioBox 44VSL and 1818VSL will have multiple Playback devices listed)
Repeat these steps for any devices listed on the Recording tab.
Reboot your computer to affect the changes.
In Studio One, please follow these instructions:
After opening up Studio One, click on the word "Studio One" in the upper right hand corner of the screen at the start page. Next click on "Options" Then click on "Advanced". Next click on "Audio". Lastly click on "Release Audio Device in Background".
Please follow all the above steps to resolve the issue that you are having.
I hope this helps.