Re: Sound bar
I'm glad to have helped.
As JBR has hinted at Carol, sometimes the sound quality of broadcast material isn't good and that might be contributing to your difficulties.
The sound level even varies within the same channel sometimes, as we found when watching the more-popular shows on BBC1 when - strangely - the sound level and clarity decreases.
The bar you like the look of might well help for those circumstances but I suspect that the root of your problem lays with the variation of broadcast sound quality.
I wonder if you have tried the shows like your "Call The Midwives" via BBC's iPlayer (if of course you have access to that) to see if the sound variance persists?
If you can try that, you might find that it helps.
I have to be honest and say that as a family we watch very, very little OverTheAir broadcast TV nowadays, far preferring streaming methods.
So it's a problem we don't have like we used to, but (for example) even my young son used to complain at having to turn the sound up when certain programmes were broadcast.
Whichever, I hope you find a solution that suits you.