Whenever I change programs (opening a video in VLC, playing a music file in a different program, or even changing sample rates in Windows settings), there's a small but noticeable pop/static through the speakers. It even does the same thing when a video file loads in a browser, or if I open a video file with no soundtrack whatsoever.
It's very annoying.
I think the Audiobox isn't silencing the audio while it's trying to change the rate to match whatever program is trying to talk to it.