First of all, this has nothing to do with BuzzTV 6. BuzzTV 6 is the software which is installed on the Powerstation devices and the L1.
Is there any question about a BuzzTV box in there ? This is a BuzzTV hardware/software support forum not a TV support forum.
If you have a specific box, post under that specific hardware section.
For TVs, I don't see the age of a TV being an issue. I am running one of my BuzzTV boxes on an archaic Audiovox TV, and I'm even using the A/V port to connect, since the TV does not even have an HDMI port. If you are having volume inconsistencies of volume/sound between channels, then the problem sounds more like an issue with your iptv service provider (and we don't discuss services here), try using a different service and see if it is just as bad.