Hi folks, I have a 3.1 onkyo with a built in amp in the subwoofer, I bought a new Sony Tv and had some trouble setting it up, turned out it was faulty so had to swap it out, also had to switch off the Bravia Sync as it was playing up with my other kit, everything working but sometimes had to turn up the volume on some channels and recodings on my Humax Freesat Foxsat HDR, had it on BBC 106 HD the news and couldn't hear any sound coming from the side speakers then moved it to Ch5 Home and away and all the sound was there, tried it on ITV HD and again the sound was there, I hadn't changed any settings on the Onkyo but wondered by switchin off the Sync from the Sony had confused things a little, usally have the volume on the Onkyo set at 25 but on some channels need to crank iot up to 30! then when watching say the Food channel have to turn it down, a bit puzzeling!

Any thoughts

The HD channels can have a full 5.1 surround sound audio track. It is entirely possible that BBC News had the newsreaders mics fed to the centre channel or the Dolby Pro-Logic circuit in the Onkyo saw a mono source, as is likely if there is a single newsreader mic panned centre of the stereo image, and fed it to the centre channel.

The other channels may have had a more stereo or surround audio mix and so there was audio fed to the L & R speakers.

As for the volume differences. The HD channels on Freeview tend to use less dynamic range compression than the SD channels. This means the average volume on HD is lower than on SD so they seem quieter even though the maximum level may be the same.