I have a condo and I want to run some Coax and twisted pair from the attic to the ground floor for service to a TV/Entertainment center.

Problem: The wall that I intend to run the wires down is 19' from ceiling to floor continuous, and on the other side of the wall is the floor of one of the bedrooms. I am pretty sure that since the wall is interior that the wall is hollow, but when I get to the floor joists of the bedroom, what can I expect to find ? The bedroom is standard 8' wood stud'ed walls probably with 2x4" across the top and bottom. My guess is that the floor joists are probably 2x10" with and end-cap that is either 1 or 2 2x10" w/1/2" plywood between for spacing.

Whats the best way to get the wires through this floor to the next wall section below ?