Past 5 year I am using airtel hd box connected to home theater through optical cable, the audio was 5.1 no doubt, but the surround effect is not enough to audible, I strongly believe that audio quality was gone though the coaxial cable, which connected between the dish and the set top box,, if you want to compare the effect of audio, the same movie if you play in a dvd player you feel the difference, I am telling about just dvd not bd disc which has true hd audio, again had a doubt, just play a movie with amazon prime video or netflix , then you will get an idea about what was true Dolby digital surround sound, my conclusion that dth platform need a lot of improvement to their equipment need to use pure digital components, which never degrade the quality of audio, thank you, from a true experiencer