I installed the trial of Boom 2 to see if I could control the audio/volume on my HDMI monitor/speakers. It works, but if I turn the volume all the way down, the sound is still pretty loud. I ran the initial configuration with the HDMI/monitor unplugged. So, currently, I have to turn the volume all the way down on the application in order to get the volume low enough. That really isn't helpful.
Boom 2 makes everything loud. This is especially true when using external speakers. Since you're volume level is really loud even when Boom 2's level is at its lowest, we'd advise that you lower your external speakers own volume level. Thanks.