I just bought a house and the previous owner had it prewired for surround. right now I am connecting my speakers through the some crappy speaker wire boxes mounted in the wall. I am going to rip out those boxes and cut the speaker wire from them. The good thing is that they used 12 gauge wire, so I am wondering how I should connect my wire to theirs? I would run the existing wire to my reciever, but it is not long enough, so I have to extend the wire somehow. Should I solder or is there some kind of connector I can buy?