I have a 5.1 setup and wondering what happens when I feed my 1909 with 7.1 sources (bitstream DDTHD and DTS-HD MA and MCPCM). Does the AVR add that information to the surround channels or discard it.
you may want to read this thread:http://www.avsforum.com/avs-vb/showthread.php?t=1148111
and this thread (which is sort of a predecessor to the one above):http://www.avsforum.com/avs-vb/showthread.php?t=1125362
It has to do mostly with the PS3, but it should still be enlightening.
The thing is that there aren't really any "true" 7.1 discrete surround mixes, as all movies are mastered in 5.1 and then a 7.1 discrete mix is simply matrixed in the mixing room (albeit using more sophisticated techniques than PLIIx). So any movie that is encoded in "7.1" is really just a "pre matrixed" 5.1 soundtrack. As such, DTHD and DTS-MA will have a 5.1 mix already encoded in the soundtrack and set by the mixer.
From my understanding, with an HDMI connection the player should "ping" the AVR for EDID information and the AVR should tell it that there are only 5.1 speakers connected. In which case, the BDP should automatically select the appropriate track (i.e. the 5.1 mix). AFAIK
, any movie that claims "7.1" will have the 7.1, 5.1, and of course 2.0 mixes already encoded in the disc. If your BDP has a setting that allows you to manually tell it you are only using a 5.1 setup, even better, as you will be sure the player is selecting the correct 5.1 mix.
Either way, the 6th/7th channels are just derived from the normal surrounds, so even if the "should happen" above doesn't work out perfectly, the receiver just downmixes those rears into the surrounds and it should still sound great.