Do you have the TV box set to Surround Sound? If turn the box volume up to 100% then turn it on.
If you have this set, and as this is your second box, I'd say there must be something within settings or connection between the TV and sound bar.
Is your TV arc enabled? If so the sound bar should be in the arc HDMI connection and the Hub in another.
Is your HDMI cable between the soundbar and TV a 4k one (if you still have the provided ones with the Hubs use both of these as these are 4k rated).
Sometimes there are individual settings on the HDMI outputs within the TV settings. It might be worth checking online for a manual to see recommended settings.
Some makes like mine (LG) recommend installing the device within it's infrastructure (more really to control it from the TV remote) Does yours?
Alternatively, find a forum for your TV and / or soundbar and ask for advice on there.
Not sure there is anything else I can advise other than resetting the box to factory settings and starting afresh with the installation.
Please remember to mark Solved Posts with Best Answer. Doing so helps other customers and saves TalkTalk's Support Team time by only looking at unsolved topics. Thanks, Steve (a fellow customer).
