I have uninstalled Boom (not sure if it was Boom or Boom 2) and I'm still seeing traces of it in my system. I don't see a Boom process running in Activity Monitor. Sometimes when I plug my headphone in, I won't get any audio, so I go to System preferences/Audio and find that my audio device is set to BoomDevice, so I switch it to Headphones and it works again. How do I remove it if I've already uninstalled Boom? Screenshot: http://i.imgur.com/578GdnP.png
It looks like you have deleted Boom 1x without uninstalling within the app.
To uninstall completely, download a trial copy of Boom 1x via www.globaldelight.com/boom-1/
Next, uninstall Boom 1x within the app via Settings>Preferences>Uninstall and check if it helps.