I recently added a sixth speaker for my 1050. Currently I am using an Oxygen Free (more or less) 12 guage line from RCA, but its very unsightly for part of the cable run and I would like to hide it better. The best way to do this seemed to be to use Monster Cable's super flat 12 guage wire for this portion of the run. The original RCA cable seems like a better fit for the portion of the run that I can easily hide and/or run under the house. Its also a whole lot cheaper.

What I am looking for are suggestions on the best way to join these two cables together. There seems to be several ways, the easiest being stripping the ends and using a twist connector. I have also seen a locking connectors for motorcycle wires that is cheap and waterproof to boot. The salesperson at The Good Guys suggested soldering the connections together and then wrapping the cables with electrical wire. Finally, I could go with a standard 12 guage butt connector or some sort of crimping solution.

Any thoughts?