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Advice for running speaker cable under floorboards and in walls

2958 Views 12 Replies 4 Participants Last post by  Cinedave
I am embarking on a big project, and since I basically have the summer off from work, I have a lot of time to work on my HT. My dedicated room is a 2nd story bonus room. I will be running cable in walls and under floorboards for the first time. I'll be using basic Proflex 14/4 cable, jacketed. My surround dipoles are wall mounted (not in-wall, just mounted to the wall. For the surrounds, I will have to go under the floor and up inside the walls to get to the speakers. Do I use a fish tape or push/pull rod of some sort to grab the cable from under the floor and pull it up inside the wall? How big of a hole do I cut into the drywall to be patched up later?

Thanks for any help you can provide.
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Fish tape will work well. Cut whatever size hole will allow you enough room to work; if you have textured walls, cut as big of a hole as you can... Textured walls are so easy to patch it isn't even funny. If your walls are not textured, then be much more careful on how big you cut as they are not as forgiving.

Good luck with ripping up floorboards. :D

Well, I don't have to rip up the floorboards, just have to make a hole where the floor is adjacent with the wall to feed the cable under the floor board and into the wall. Do I need a special connector for the fish tape to hold the cable or do I just tie it with a string or something? Also, barring that there are no studs in the way, will I have a clear path from under the floor boards to inside the wall?
Originally posted by Cinedave
Do I need a special connector for the fish tape to hold the cable or do I just tie it with a string or something?
The fish tape will have a loop on the end. After pushing the fish tape where you want the cable to be run, attach the cable to the fish tape. You need a mechanical bond (fish tape to cable) that will survive the pull. The more difficult the pull the more effort required to make a good bond. You'll need to loop the cable through the fish tape loop then tape the cable loop so that the bond is as smooth as possible. This would be much easier to show than describe. If it's a short run through a large hole the bond is not that critical. If there is even the remotest possibility that you'll want to run more wires along the same route, then at the same time pull a heavy string through with the cable. The string can be used later to pull more cables.

You can use a stud finder to see what may be in the wall.
How do you get a fish tape to make a 90 degree bend? I'd be feeding a fish tape from the speaker location on the wall, down to a floorboard hole right next to that wall.
I'm not sure I understand where this wire is coming from. By floorboard do you mean the wooden subfloor or the wood trim at the bottom of wall? If the latter, then feed the fish tape in at the bottom hole. It can deflect off the outer surface of the wall (or off the insulation) but you may need long pliers or a hook through the upper hole to catch it.
Okay, imagine an "L", a 90 degree angle. The verticle part of the L is the wall and the horizontal part of the L is the wooden subfloor. Somewhere on the wall is a hole to allow speaker cable to come out and into the speaker. Down below, the speaker cable is running along the subfloor, under the carpet. Before this cable reaches the speaker, I want to fully hide it. My question is, can I drill a hole in the subfloor right up against the wall (the baseboard will be added later), then, start dropping my cable through the hole where the speaker is mounted and somehow be able to feed it through the subfloor hole so that I can run it down the floor under the carpet? I hope that makes sense :confused:
So the horizontal portion of the run will be between the carpet and subfloor? It might be better behind the baseboard since you'll be adding them later. Anyway back to your question - no that would be difficult because it's more like a 180 degree bend isn't it? Plus at the bottom of the wall, above the subfloor is a horizontal sole plate (2x4 or 2x6 or whatever). So you'd need a hole in the wall at the speaker, a hole in the sole plate then subfloor inside the wall and another hole in the subfloor inside the room. If you run them behind the baseboard, you can put a small (wire size) hole in the wall just above the sole plate. It's an easy feed from there.

An alternative would be to feed from the top. Is the space above the room accessible? Like an attic? I assume the room below is finished and the space above its ceiling is not accessible.
The space below the HT room is the 3 car garage. Above the room is the roof. The attic actually ends at the inside wall (north wall) of the HT room, basically leaving no attic space to work with. Back to the baseboard thing:

I am installing new oak baseboards that are pretty big, about 5" vertical. If I run cable behind the baseboard (it's 14/4 cable with a jacket) how would I have room to fasten the baseboard flush to the wall? Seems like the cable is too thick for that but it would be great.
Between the drywall or plaster and the subfloor - assuming the cable will fit. You may have to chisel off some of the drywall at the bottom. Or take some material off the back of the baseboard. Or a combination of the two. It's a bit more work but you've got time and it's got to be better than lumpy carpet. ;)
If I could find someone that has a shaper, I would have someone mill a cove into contact side of the baseboard. Chiseling the wall? No way. Do you know how much wall I would have to do? Over 50 feet! Sorry I don't have the back for that. I have a center channel speaker cable that I'm going to have to run to the opposite side of the room too. I'm hoping that I can run it straight down the center of the room and it will be at least at the level of the carpet padding so as not to create a lump.

Thanks HarmsWay for all your suggestions. I have a heck of a project ahead of me!
the fishing you are describing is very hard to do. I bet your floor joists have braces in them. either X or solid but guaranteed to hang up your tape. I would go the baseboard approach

buy an inexpensive router if you cant get access to a shaper. Best bet is to mount it in a router table (i.e. poor mans shaper) but you can also hand do it with a straight edge for a guide. I love projects like this 'cause it gives me a good excuse to buy tools. (Gee, honey, look how much money we're saving)

I'd avoid running the winre under carpet as it will be obvious when some one steps on it. Since it sounds like you are doing the baseboard thing, I'd add it to that. You can go over doorways by (carefully) pulling off the trim and running in the void that is between to jamb and the drywall.

If you decide to run wire under the rug, there is flat speaker wire that might be worth looking at. Also, you can cut the pad and pull it apart by the width of the wire.

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Philba, I do have a decent router table with a 3-horse DeWalt mounted to it that I guess will do the job. I just need someone on the other end of the workpiece to grab it. Anyway, it shouldn't be a problem doing some kind of roundover big enough to get the cable jacket in. Thanks!

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