Come on Elephas, you know the itch is growing inside and you need to succumb to it. Just get a RS a WES or both, play with your tubes and then let us know
What play back software are you using? In Foobar for instance (and most others too) you need to choose in Preferences the output device you've decided to use. AFAIK it doesn't allow to use two output devices at the same time. Other players can do that, but I'm not familiar with them.