Regarding your query, usually Boom switches automatically by itself when any audio output device is connected or removed from the system. As for troubleshooting, as an "Audio input" please select the input device i.e "Built-in Microphone or Mic. Only as an output, select the output device which is active, which will then revert to BoomDevice in "System Sound Preference" and Skpye Audio preference (refer screen shot below).
Note:
Ideally when Boom is active, BoomDevice would be selected. It also depend on which external Output is being used. If you have been using internal speakers then click on the internal speakers or if any other external device like speakers, headphones (if Boom is active then the selection reverts to BoomDevice, this is normal), now play any audio file on your system and check if you can hear the boosted sound.
Comments
Regarding your query, usually Boom switches automatically by itself when any audio output device is connected or removed from the system.
As for troubleshooting, as an "Audio input" please select the input device i.e "Built-in Microphone or Mic.
Only as an output, select the output device which is active, which will then revert to BoomDevice in "System Sound Preference" and Skpye Audio preference (refer screen shot below).
Note:
Ideally when Boom is active, BoomDevice would be selected. It also depend on which external Output is being used. If you have been using internal speakers then click on the internal speakers or if any other external device like speakers, headphones (if Boom is active then the selection reverts to BoomDevice, this is normal), now play any audio file on your system and check if you can hear the boosted sound.