media room in an unfinished space

I'm setting up a media space/room in an unfinished basement. It has a concrete floor, exposed ceiling (you can see the joists), three unfinished walls and the fourth side where the furnace and entrance to the space is. Needless to say the sound travels upstairs to the main floor and its relatively loud. How can I kind of sound proof this space so that it doesn't annoy my family upstairs?

Thanks in advance