But dont u think that if its 7.1, then the amp shud show it 7.1, irrespective of the speakers connected? Coz i dont think Amp shud be dependant on the no. of speakers connected!
And another question that has come is.......does it mean that when u turn to SD channels it shows "Stereo or 2.1" and for HD it shows "5.1"? I have no idea how this device functions!
That depends on how you set-up the amp and what your input source is. Yes, when you switch to an SD channel the amp shows that it is receiving a Stereo audio feed and when you switch to an HD channel it shows that it is receiving a Dolby Digital 5.1 audio feed. This is what I meant earlier when I used the term multi channel audio.
You can use any home theatre amp to simulate multi channel audio over 5.1/7.1/9.1 speakers even when your input signal is only stereo. As you might imagine, this is not true multi channel audio. Today, only a properly coded 5.1/7.1 audio feed is a real multi channel audio feed. Back in the day there were other standards such as Dolby Pro Logic which gave you discrete front left, centre and right audio and a combined rear audio channel, but these are now obsolete. The current multi-channel audio standards are Dolby True HD and DTS-HD Master, both of which offer uncompressed audio over 5.1/7.1 channels and are the current Bluray audio standard.
Edit: Also the SD channels are Stereo only. There is no .1 in a stereo feed. The .1 in any multi-channel audio format refers to the LFE (Low frequency effects) channel which feeds only low frequency info to a subwoofer(s).