I did a review of that system for the Shack.
http://www.hometheatershack.com/foru...er-system.html
The Z5500 can fill a pretty big space, but just how big will depend on that exact room and just how particular you are. Its certainly a very cheap system to try out. If it doesn't work out in your 15x25 room, you could just put it in an office or bedroom.