The Audio Return Channel in HDMI 1.4 enables a TV, via a single HDMI cable, to send audio data upstream to an A/V receiver or surround audio controller, increasing user flexibility and eliminating the need for any separate S/PDIF audio connection.
I could not ascertain if the tv supports ARC but the onkyo 3500 does. Lets look at 2 scenario's ........ with ARC and without ARC.
ARC ON
1 HDMI 1.4 cable from AVR to TV
All other devices like DVD Player, Blueray Player, cable STB, etc will be connected directly to the AVR and not the tv.
You need to enable ARC on the tv and the AVR.
ARC OFF
1 HDMI cable from AVR to TV
1 optical cable from TV Optical Digital Audio Output out to AVR Optical Digital Audio input.
Airtel STB
1 HDMI 1.3 cable from STB to AVR
1 optical cable from STB Optical Digital Audio Output to AVR Optical Digital Audio input.
The above hook up plan will give you 5.1 and would be the best way to connect all your devices. Until Airtel supports 5.1 audio over HDMI this would be the best way to do it. Once they do support 5.1 audio over HDMI, you can remove the optical cable from the STB and only use a single HDMI cable.
Also ensure, to use ARC you need HDMI 1.4 and not 1.3.
