I'd like to find some sort of simple powered system for listening to music in my room. I'd like two small speakers for my nightstands, plus a powered subwoofer. Mostly this would be for music at low levels as I fall asleep or wake up. Occasionally it would be louder when I am working around the house. The music source will be a Mac Mini I use as a music server, via the headphones port on the Mini. Suggestions?