The set is about three years old and the problem has been getting worse recently.
I am watching Freeview via an aerial.
I am sorry. I have misled you. My television is a Toshiba, NOT Hitachi. Can you still help?
I have played two pr0fessional DVDs and the sound is still muffled.
Yes, I am willing to give it a go. Where do I get one from?Brian