I just downloaded the AVM70 manual to look at the back panel and now I am a bit confused as well. All I see are stereo RCA inputs, optical in, coax and HDMI. How would you connect a 2.1 or 5.1 RCA output to the AVM70? There are no 5.1 analogue inputs. If the goal is to run DLBC on the laptop, would you not need to use a digital connection to the AVM70 to get the subwwoofer channel? Running analogue stereo to the AVP and stripping out the subwoofer channel wouldn't work. I probably have this all wrong.
Could you list all of the equipment in the chain?