I feel your pain. I had the same problem. I drilled a 1 inch hole in the bottom of the wall and used a "fish tape" to push the wire to the corner of the room. (Use a drill bit that cut holes...do not use small drill bits to "make a hole" and keep the plugs of drywall, you will need them) I then drilled another 1 inch hole in the adjoining wall so that I could pull the wires around the corner. I used the fish tape to run both pair of of wires to the back of the room and did the same thing again to get past the corner. When I got to the location on the wall where I wanted the first speaker, I drilled hole in the proposed speaker location and pulled the wire through. I then used the fish tape to move the other speaker wire to the desired location. Here's the catch: you need to have a wall that is continuous i.e. without a doorway and it requires a significant amount of speker wire to do it that way. You will have to precut the wire and I would recommend making sure that the lengths are prettly close to being the same for both pair.
After you are done...you will have holes in your wall...take each of the drywall plugs and drill a small hole in the middle..stick a nail through the back side that is is about an inch or so longer than the drywall is thick...put a plug in a hole so that the head of the nail is in the wall and the point is facing you, hold onto the nail and spackle the area around the plug...it..after the spackle is dry..just push the nail into the plug and paint.
It is worth the work if you don't want to see wires.
