Have a look at my center channel stand. It performs exactly the function you describe. I originally built it for my cable box but you can see at the bottom where I added a couple of felt strips to raise it to fit my sat. box.
I bought a piece of shelving at home depot and had them cut it for me into a top shelf and two short risers. Then I brought the pieces home and screwed the risers to the shelf. Simple. Cheap. Effective.