I am with "Rudy 1" on this one. I most definitely get 5.1 sound from my Sony tv that is connected to my cable box through HDMI, and to my AVR via optical cable. On a channel indicating a DD 5.1 signal (per the info from the cable box display), the audio information coming from the front L & R speakers is completely different than from the center channel, as is the audio from the surround speakers. When that is happening my AVR (an Onkyo) only indicates DD, and the sound from each channel is, without question, discrete--it is absolutely not a 2.1 signal. On a channel that does not indicate it is transmitting 5.1, my AVR will usually process a "ProLogic" signal, which is NOT an entirely discrete signal for each channel. But when it is doing that, the display on my AVR always indicates it is a ProLogic signal.