I just bought some in-ceiling speakers to round out my surround system.It was the only option acceptable to Admiral Wife. These are going on the first floor of a two story house with basement. My only real option is to go through an outside wall, down into the basement and over to the area where my TV and electronics reside. Getting the wire up to the amplifiers is simple. I wondered if anyone had tips about getting the wires from the ceiling to the basement. I have spray foam insulation to complicate matters, but I think I have a good 1" space between drywall and foam. Also, there is a firestop at 8' inside the wall(9' walls). Luckily, I will be cutting about a 12" square for the speaker right near the wall, so I can work through that space. The joists are 12" too, so I have some height. Walls are 2x6. I am assuming I will need a right angle drill to go down 3" through the top plate and bottom of that rim joist. How big of a hole? It's getting down to, and through, the firestop that makes me nervous. Flex bit? Extensions to a rigid bit? Suggestions? I was just at Lowes and the flex bits they had were minimum 36"(and were not very flexible), which won't work, and of course they were out of extensions so I couldn't even look. I was thinking a 6" extension on a 12" spade bit might work if I slip the long bit through the first hole before I tighten on the extension. Any and all advice appreciated.