Recently one of my friends discovered that if an SX10 is downgraded from CE8.x to TC7.x , then audio is no longer carried over the HDMI output. After some experimentation he realized that the Configuration – Experimental – “Audio AudibleAndAudioPairingSoundRouting” is set to to ‘Split’ and THIS is what turns off HDMI audio out. The correct setting should be: ‘HdmiAndLineOut’.

Note that the “experimental” menu is hidden in the web interface, so you’ll have to search for “Experimental” to reveal this menu.

The SSH command would be:

xConfiguration Experimental Audio AudibleAndAudioPairingSoundRouting: HdmiAndLineOut

Thanks for the tip Theis.