Freesey, I've tried to interpret your schematic and what you've written, but it's still unclear. The most common connection scheme would be to have a single length of co-axial cable running from the sub out on the receiver to the line level input on the sub. No other connection to the sub would be necessary. Then you you would have 5 lengths of speaker wire running from the main, center, and surround outputs on the receiver to those speakers( not to the sub at all). How are your speakers connected presently? Even that isn't clear to me.
