I have a similar system. Since its an all in one system, panasonic didnt want to include any inputs that would allow 5.1( coaxial or optical). I only have two composite inputs in mine. So its basically a home theater system just for the built in dvd player. If you wanted to hook up anything else( hd-dvd, ps3, etc.) it cant have 5.1. I dont mind too much, cuz I got it for really cheap.