I’ve got a BT youview digi box thingy, plugged into the tele on HDMi 1 with a bogo HDMi lead and also have a Now TV box plugged in to HDMi 2 with another bogo HDMi lead.

On the Youview box to get a decent watchable / listenable volume level if you say have it set at 60% on the box the tele needs to be around 50%, on the Now TV box you have the tele at 20% for the same volume output.

Any clues as to why they differ so much and if anything can be done about it?

I don’t know about either of those boxes, but some set-top boxes have their own volume controls so that you can turn it down below maximum volume. It sounds like that’s what you’re describing on the YV box? in which case, slap it at 100% and then leave it alone, control the volume with the TV.

Set your Youview box output to 100%?

EDIT: What he said

Cheers

..in which case, slap it at 100% and then leave it alone, control the volume with the TV.

This assumes you live on your own and there aren’t another four people doing their own thing with the remotes, one of whom has zero capacity of understanding anything other than pressing 1 gets you BBC 1 (in cataract-o-scope; she knows who she is…). Or you can exert Fat Kim levels of dictatorial control.

Or you can exert Fat Kim levels of dictatorial control.

Or do what I’ve done and get a Logitech Harmony and map the volume to the TV (or amp) itself and hide all the other remotes.