In reply to Climbing Pieman:
Thanks for the help. I thought this morning that I'd cracked it. I made sure that the TV speakers were off then jiggled around with the volume and bass settings. I was watching a current affairs programme and I had the sound level at about half of what I would have had it pre-sound bar.
We then sat down about half an hour ago to watch a film we'd recorded last night but were back at square one. With the sound level set Hugh Bonneville, who I consider to be a good actor and speaker, appeared to be mumbling as did the many Americans. If they weren't mumbling they were shouting which rendered them equally inaudible. There was then a terrible explosion of background music which deafened us with huge BOOM, BOOM and reverberated around the room.
We switched it off
This only bears out my feeling that the sound in films and plays is, for some reason or other, inferior to that of things like news broadcasts and current affairs. I NEVER have any difficulty listening to George Allagiah.