Speaker cable to hook up a 12v AC trigger?


I am trying to hook up a 12v trigger to shut down my amplifiers. I have an extra run of speaker cable going from my preamp to the amplifiers, they are monoblocks and are about 50ft away. Will speaker cable work? I know I would have to solder the plugs onto it. Will the 12v signal carry that far? Any help would be appreciated...
iramirez