I am guessing you are talking about the fuse for the power wire of the amp... You would want that as close to the battery as you can get it. I mounted mine right next to the fuse box in the GTO.

 

Recomended is no more than 18 inches from your battery.

 

Thats what I thought, there's a nice little spot to mount it on the tray that holds the throttle cable actuator.