Question about setting up Sirius in home [View all]

I'm "technically challenged" and am trying to set up sirius radio in my home. My account allows for my car (love it!) and streaming. Got a sirius in home kit and a speakers docking box. Called sirius to set up inhome account. I set the receiver in the dock, fired it up, got the channels to show up. Had to adjust antenna in south window. Got 100% reception for satelite.
All this, and no sound!
First of all, why south facing window? Am I looking for more sunlight, or to connect to a satelite? Second, why no sound if I have full satelite connection? I don't have a teenager around to help me. Any suggestions? Thanks.