I want to run four rear speakers (2 x right and 2 x left with a view to eventually upgrading the second set for EX/ES). I currently have the DSPE800 which can drive between 4-16 Ohms. Does the impedance halve or double when running two sets from 1 set of binding posts? Ie if I run two sets of rear speakers with an impedance rating of 8 ohms will the impedance for each rear channel equal 4 or 16 ohms? And when running two sets is it best to spur the second off the first or run seperate cables (as you would when bi-wiring)? I am going to build the four rear speakers into the walls to hide as best as possible. Can anyone recommend speakers for this (bearing the above in mind)? I was thinking about some small Tannoy's and then changing the grill fabric to match the decor. Any helpful advice would be much appreciated.