Whoa, CAPS LOCK off please!
When you say you're getting 'very bad sound', do you mean distortion? Buzzing?
I must admit, fantastic though its TVs, Blu-ray players and DVD recorders are, we haven't found a Panasonic cinema system lately that we'd rate (the speakers normally let them down). If it's just a rather bright, harsh sound, it could just be the system doing its thing.
Give us some more info and we'll see if we can help.