I have a foxpro with a remote control. I put it about 50 yards away, at a right angle to the approach I am expecting. I also have a little decoy that looks like a rabbit and wiggles back and forth. That goes next to the speaker. It gives the critters something to look at when they are coming in. In your case, you could put the speaker and decoy 50 yards down the fence line. A few weeks ago, one of my buddies who uses the same setup had a coyote get a hold of his decoy it came in so fast. After administering a healthy dose of #4 buck, he retrieved his decoy from the would be thief.
