Running Speaker Wire through Drywall

Hi is this an inside wall or exterior wall your trying to run the wire through down to the basement? Are you planning to bring the wire back up through an opposite wall on the same floor?
Yes your exterior walls have insulation inside them. Your interior wall should be open between the studs.

If your doing what I think you trying to do. You need a flex drill bit.

You can trace and cut your holes for the wall plates. Use those holes in the walls to drill down into the basement. Email me the pics and I'll try to help you the best I can.

I assume your home is stick framing.
Putting a hole through the wall, between the studs will get you into the wall cavity. You will still have a bottom plate and sub floor you will need to get through. You can drill up through the sub floor and plate from the basement.

The trick is to find the exact area in the basement to drill the hole.

* Pick the wall space area where you would like to make the wall penetration.
* Next step you will need a drill and a 1/16 to 1/8 inch bit.
* Measure out from the Sheetrock wall, say 2 inches, and drill a small hole all the way through the floor. ( Word of caution here! If you have radiant heat in the floor do not drill.)
* Next insert a piece of wire through the hole about 12 inches. Go to the basement and look for the wire.
* Measure back from the wire 2 inches, (drilled hole to sheet rock) + thickness of rock + about 1 1/2 inches ( approx 4 total inches). Look for nails/s sticking through sub floor sheathing. Drill a 3/4 to 1 inch up through floor and plate.

* If the wall you are wanting to use is an outside wall it can be a little tricky depending on the drill you will be using. An Angle drill works the best. Because of the foundation wall and seal plate you may have to angle the drill bit to drill the hole with a regular drill. In this instance you will have to be careful and not drill out through the outside of the house..... LOL, seeing daylight is a bad sign..... Because you will be drilling at an angle shorten up the distance back from the locator wire. Only measure back about 2 1/2 to 3 inches. Carefully drill hole with a 1 inch bit.

Well, no basements where I live but I guess one way would be to find a stud behind the drywall with a studfinder, cut a hole next to the stud (not directly in front of it), insert drill with a right angle attachment and wood bit and drill a hole through the sill plate down to the basement or if you know where everything is located then you can drill up from the basement. That may be easier or not but won't require such a long wood bit which you probably don't have. If the foamy material (polyurethane?) is just a layer in the basement drill right through it. There will still be a double stud to go through. If it is in the wall cavity I would definitely drill straight up from the basement. Make sure you determine that there is no romex where you are drilling. Fish the cable with a stiff wire up to the next floor (hope it's just one floor). You will have to install a electrical outlet box with wings that hold it in place against the drywall in the hole you cut in the upstairs room. Don't cut too big just the size of the outlet box. Then a cable outlet cover plate should work. And a can of the foamy stuff to seal the box and the hole you drilled. You'll never fish it up or down without the electrical box opening. Make sure you run it through the box before installing. Oh yea the fun part is determining where the wall studs are located upstairs if you start in the basement so factor that in while deciding which room to drill from. Have fun!

Ha! Two answers popped up while I typed. And they even added paragraphs! Jea48 gives good advice in these areas. Cheers!

Low voltage bracket for existing Sheetrock or plaster walls.
Best not to get too close to wall studs, stay a few inches away. Just never know what may be fastened to the stud inside the wall...

If an interior wall always check the other side of the wall. Make sure something is not already in the space.

Also roughly check the location in the basement before you cut the opening in the wall. Make sure the area below is accessible. Look for duct work that may prohibit access from the basement.