cat6 return audio baluns either analog or digital depending on the the tv and audio matrix. If using analog I like tranformative engineering sb1, psb1, or psb2 depending on needs , if the tv is on an avr then the tv likely wont be fed audio over the hdmi output. I use the zone2 of my avr since it has a hdmi dac and created a virtual room and tv off of the zone2 output that programatically follows th emain zone and plug that into the audio matrix for the ability to overflow that to the zone audio system.