I have a panny bluray hooked up tomy onkyo receiver ''506'' which is pass thru,I was watching a movie and saw pcm on my receiver not really knowing exactly what pcm was I went to my blue ray menu and changed some of the bit streaming formats know everything comes out dolby digital ,would pcm have sounded better than dolby digital ? as you can see I am a newbie but am having fun learning about my home theater thanks for your help.