I've just checked it out. On my tiny little 4" telly on my desk (which I use to watch TV) the sound produced by its tinny little speakers failed to push the lead singer's voice ahead of the sound of his backing group (making it sound rather 'mushy') but plugging in my good-quality wireless headphones produced excellent audio. Perhaps your TV has got speakers that are good at handling high frequencies but lousy at coping with bass frequencies?
The sound sometimes goes a bit iffy but I am using a cheap Tesco Value Freeview+HD box outside the UK. If it acts the bollix I just turn it off and turn it on again and it is fine. Sometimes struggles with the MPEG4 encryption on the local and HD channels but I guess you get what you pay for.