Inwall wiring question

[notphilmitchell]

My wife proclaimed that I must make the black boxes go away...

So, I'm going to use Paradigm AMS-100R (in-ceiling) speakers for my surrounds. Fortunately there is a chase which affords me access to run the wires up into the ceiling. It has open joists so it will be easy to use a fish tape to get them where I want it.

My questions are:

What is the difference between regular speaker wire and that designated for in-wall use? I've seen rolls of both 2 wire and 4 wire in-wall cable. I presume the 4 wire is intended for where there is only room to run 1 cable? How do you connect the two separate speakers from a 4 wire cable- do you just cut a slit in the cable jacket and pull out the two wires for speaker 1 and then continue with only two wires in the jacket on to speaker 2? As getting the cables up into the ceiling isn't really a problem, does it make sense to use 2 or 4 wire cable?

The total cable lenght is going to be about 40 feet. The cable I was planning on using is 16gauge. Is that sufficient?

Thanks for your help!

[Rich-n-Texas]

Just as an FYI, I used 12 gauge OFC wire when I ran it for the surrounds on the opposite wall. Total length was about 50 feet up one 10 foot wall, through the attic and then down another ten foot wall. In my opinion 16 gauge is too thin, especially for distances in the 40 - 50' range. I understand that construction grade wire, whether two pairs or four are used to meet electrical code, but to me that's not important. What gauge wire are you going to use on the home run (wall to source)?

[notphilmitchell]

I hadn't really thought about the home run (source to wall) and the wall jacks. Currently, my surrounds (Paradigm ADP 370- don't worry, they are being relocated to what will become the primary viewing room) are connected by a six meter (20 ft) pair of Tara Labs Helix 6 cables (12 gauge). I got these for about 80% off retail and don't really believe they make a sonic difference but think they look cool as the speakers are on stands.

Whatever perceived benefit is going to be lost by going with in-wall wiring. I think that I will be forming a bit of a bottleneck with the whole wall plate thing - I was planning on putting in Pass & Seymour brand (available from a big box DIY store) modular binding posts / wall plate where they enter the wall. I was going to use Monster cable 16 (2 or 4 wire) for the inwall cable. I'd rather order the wallplates and the cable from Parts Express but want to get started on this tomorrow evening.

I need about four feet of source to wall cable to allow for comfortably pulling out the reciever out of the cabinet so I imagine I will just cut a couple pieces of some old 12 guage OFC Monster cable that pre-dated the Tara cables.

[Groundbeef]

I think "in-wall" wiring has different construction than regular wire. Typically it is going to have some sort of sheath or wrapping to help prevent chaffing when "pulling" it through the wall.

Not going to do you much good to pull the wire, and then subsequently burn the house down due to some short in the wiring. Remeber, electrical fires are the #1 reason for homes catching fire. And it doesn't take long for wiring to go if damaged.

It might not be as big a problem in new construction if you can get in early before the sheetrock is hung, because you can see exactly where (and what) the wiring is going to be against.

I would use the "in-wall" just for peace of mind.

[Rich-n-Texas]

Well beefy, I'd agree but how could a short in speaker wiring cause a fire?

If he's using 12 gauge and then connecting it to 16 gauge his weakest link now becomes the 16 gauge wire right?

I've had the 12 gauge "rope" wire with clear insulation up in my attic for two very drastic seasonal cycles now and there's no sign of insulation breakdown. Even if it did and it caused a short I'd know right away. In my case, there's nothing that the wire could possibly rub against to cause a nick in the insulation since I'm not using junction type boxes, and there's no wall insulation to worry about.

[Groundbeef]

Well beefy, I'd agree but how could a short in speaker wiring cause a fire?

If he's using 12 gauge and then connecting it to 16 gauge his weakest link now becomes the 16 gauge wire right?

I've had the 12 gauge "rope" wire with clear insulation up in my attic for two very drastic seasonal cycles now and there's no sign of insulation breakdown. Even if it did and it caused a short I'd know right away. In my case, there's nothing that the wire could possibly rub against to cause a nick in the insulation since I'm not using junction type boxes, and there's no wall insulation to worry about.

I'm not suggesting that the insulation will "breakdown" as you put it. The problem can arise when "pulling" the wire through the wall. I'm not sure how much home construction you have done, but when walls and ceilings are hung, the workers are not always "perfect". Nails, staples, and God knows what else are sometimes out of the wood, left behind or otherwise.

The extra insulation (coating) can help prevent the actual wire from chafing when passing the above mentioned obstructions.

Can it be a problem for the OP? Yes, there is a possibility that there will be no problems. I would be willing to bet there won't be any problems. But for the difference in speaker wire cost, why not go the extra for the insulated wiring?

As for starting a fire, I'm not an electrician. However, as electrical fires are the #1 reason for home fires, its not a bad decision to wire with IN WALL wires.

http://www.insweb.com/insurance/home_insurance/electrical_fires_homeowners_insurnace.htm

It doesn't take much electricty in a short to cause a fire. Case in point. Take a 4" wire (uninsulated) and put 1 end on each end of a AA battery. I'm willing to bet you can't hold it there for too long before you fingers begin smoking. And thats only a AA. And thats what can happen if your wiring becomes exposed pulling it through an unknown area.

Just my opinion, your milage may vary.

[notphilmitchell]

That's something I never even thought about because I just assumed it was low-voltage. It makes sense to go with a in-wall rated cable. Any concerns about it going over a heat run?

Any thoughts about 2 versus 4 wire cable? My other thought about making a slit in the cable and pulling the two wires for speaker 1 out of a four wire cable (keeping the sheath intact) and continuing on to speaker 2 would be to cut the cable and splice it with wire nuts. This didn't seem to be as good an idea to me.

[Rich-n-Texas]

Fortunately there is a chase which affords me access to run the wires up into the ceiling. It has open joists so it will be easy to use a fish tape to get them where I want it.
This tells me he probably won't run into jagged edges while routing his wires.

I have no experience with home construction but I have plenty of experience crawling around in my attic. Yes, I run into areas where there are nails sticking out, splintered wood etc. When I was running the wiring, I drilled holes in the plates between the studs where I needed to run the wiring down the wall, and I always made sure the hole was clear of splintered wood (usually with a glove on) first.

Batteries, even AA batteries are capable of producing a lot of current. I don't think that's an accurate comparison to the output of an amp, although it may be that if the volume is high enough it could create an excessive amount of heat, but wouldn't that trigger the source's protection mode?
I still say though that no matter what, he should use 12 gauge wire from end to end.

[Groundbeef]

Hey, no arguement here. I'm just saying, that if it were my house, I'd use the in-wall rated cable. In fact, I did use it when I finished my basement.

I would agree on the 12 gauge, but still use the in wall rated wire.

As far as voltage protection kicking in? Yes, most likely it would. But why rely on a safety switch when you can do it right the first time.

I have GFI switches in my bathroom. I don't care how "safe" they are, I'm not willing to allow my wife to toss the hair dryer into the tub when I'm taking a bath. It's nice to know that there is protection to prevent accidents, but that doesn't override jurisprudence when setting up the system.

As far as the AA example goes, it is a fair method to prove a point. Electricity is a funny beast, and I for one am not willing to screw with it. And I didn't check the OP's equipment, but does it even have overload cutoff? Depending upong age it may not. And you wouldn't belive how many knuckleheads cut the 3rd prong off equipment to make it work in older homes!

Passing your wires over your heat duct would probably NOT cause a problem. It all depends how far from the furnace it is as well. If its past 20' or so from the furnace, no problems should arise.

The problem with running along furnace ducts are that the exposed steel edges are RAZOR sharp unless your installer bent them down. The steel can snag, cut, or otherwise mess up things that pass over. Just be careful, and if you feel resistance, move it around a bit, don't just pull harder!

[Luvin Da Blues]

In wall wiring usually has a fire spread rating that ordinary wiring will not have.

[Rich-n-Texas]

Hey, no arguement here. I'm just saying, that if it were my house, I'd use the in-wall rated cable. In fact, I did use it when I finished my basement.

I would agree on the 12 gauge, but still use the in wall rated wire.
I agree as well. If you have nice (and expensive) 12 gauge wire for the home runs and you mix in 16 gauge IMO you've rendered the perceived benefit of using the Tara Labs cable useless.


As far as voltage protection kicking in? Yes, most likely it would. But why rely on a safety switch when you can do it right the first time.
Oooh! I never thought about doing it right the first time. I'm not good at planning that far ahead, trust me. :smilewinkgrin:


I have GFI switches in my bathroom. I don't care how "safe" they are, I'm not willing to allow my wife to toss the hair dryer into the tub when I'm taking a bath. It's nice to know that there is protection to prevent accidents, but that doesn't override jurisprudence when setting up the system.
Now beefy, why would your wife ever want to throw a hair dryer in the bathtub while you're in it? :lol: With your sense of humor? Naaaaa...


As far as the AA example goes, it is a fair method to prove a point. Electricity is a funny beast, and I for one am not willing to screw with it. And I didn't check the OP's equipment, but does it even have overload cutoff? Depending upong age it may not.
Yes, it's quite possible his equipment doesn't have overload protection. That thought crossed my mind later.

And you wouldn't belive how many knuckleheads cut the 3rd prong off equipment to make it work in older homes!
Oh yes I would. Remember, I work in an engineering lab. :yikes:


Passing your wires over your heat duct would probably NOT cause a problem. It all depends how far from the furnace it is as well. If its past 20' or so from the furnace, no problems should arise.

The problem with running along furnace ducts are that the exposed steel edges are RAZOR sharp unless your installer bent them down. The steel can snag, cut, or otherwise mess up things that pass over. Just be careful, and if you feel resistance, move it around a bit, don't just pull harder!
I've always used the 'if it don't fit force it" methodology. :ihih:

(Man! This Home theater hobby is EXPENSIVE!!!)