I don't have my surround speakers hooked up yet. just my mains front and sub. On my reciever it has ports for multi channel in. Do i need to use that or digital coax or optical to recieve a dolby digital or DTS signal. current i just have an audio cable out from my dvd player and into my reciever. I seems to automaticaly go into prologic and I see nothing indicating it is in DD. Also there is no sound comming out of my sub. which is sub out on reciever and LFE in on the sub. Do I need to have my dvd hooked up via digital coax or optical to get 5.1 ?