Speaker Wire for Home Electrical?

Just curious on what everybody thinks about using stranded speaker wire for home electrical applications.  For instance, putting lights on the back porch....would the stranded car audio speaker wire have drawbacks against solid core home wire.  Wattage on the lights would be around 100W-150W.  can't see weather being an inhibitor as cars deal with the same if not more severe elements.  Ground would be a solid core wire but the other two wires would be stranded 12-16 ga. rockford speaker wire.  Thanks for your opinions...Howie, idiot, haemphyst, kind of want to know what you guys think, but of course, anybody's opinions are welcome! 

Thanks       

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...half of the truth can be worse than a lie. <----Roger Russell said that..

I'm curious about the answers that you'll get to this. I know that we use stranded wire in car audio because vibrations can cause a solid core to break, but I don't know about the reverse application.

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MECP Basic Installation Tech
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Stranded wire should be left for lamp cords.

It is going to be application specific but in short; if you are installing something that needs to be hard wired, it should be wired with solid 14ga or 12ga wire.

Now I've purchased different under cabinet lighting for example that comes with stranded 16 or 18 gauge wire (again "lamp cord") that you plug into the wall. These don't use a ground wire so its just 2 conductor wire. Also that wire is not rated for in-wall use.

I am guessing that you already have an abundance of speaker wire and that is why you are asking the question. If you want to know for your particular application if it would be acceptable, then some more details would help.

As always, check your local electrical codes for specifics.

Yup that's pretty much why....i think most installers have an abundace of wire!  What i'm thinking to do is use the speaker wire to run two set of lights off the back porch, to light the backyard.  Each set has two lights on it and can be adjusted to set the desired lighting arrangement.  As it stands right now there is a porch light back there but the light on that is ridiculous, so i'm thinking of tapping into the power there and run the new lights off the same wire(same switch).  The lights themselves are 150W but am thinking of dropping that to 75W or 100W.

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...half of the truth can be worse than a lie. <----Roger Russell said that..

I assume you are NOT talking about mains/AC wiring!!(?)


(Never use non-approved cable & fittings for (domestic) AC systems.
And if not also illegal, that is also recommended in reverse - do not use (domestic mains) AC cable for DC and signaling.)

Peter I think that they are asking about that.  I know wire has increased in price a good bit lately, spend the money on some wire today, or spend some money to rebuild your house tomorrow.  I am sure this would be a violation of dozens of safety codes, and a BAD idea. 

People often find out such breaches when their insurance company (rightfully) refuses to pay anything despite complete loss of house and contents.


The mains/wall wiring approval should be easy to accept or understand.
The opposite may not be obvious - eg, using mains/AC/wall wires or sockets for DC car & trailer connections, or intercoms, etc - it took me a while to understand, and that was before dc-ac inverters became common!

DO NOT mix cable types unless you are certain of the electrical impacts and any Regulatory issues.   


....I am using (heavy) fig-8 speaker cable for my relay-switched car headlights..... (Temporarily of course!!)

I am an electrical contractor, I hold degrees in Electrical Technology and Industrial Electronics, and am currently working on my Electrical Engineering degree. The short answer to this question is "DON'T DO IT!" The reason, automotive speaker wire is not approved by the National Electrical Code (aka NEC) for ANY household load application.

Now, the long answers, Can it be done? Yes. Should it be done? No (See NEC). Issues IF it is done? Most speaker wire is 16 ga or smaller. House wiring is 14 ga or larger (most times 12 ga is the smallest used). This is due to the current loads of the devices they connect. If you use a wire too small for the load, you run the risk of starting a fire, and if/when an investigation is done for the cause and they find speaker wire, the insurance company will not pay due to unapproved electrical installation.

So, while I have used a short piece of speaker wire to do a quick test or power something for a EXTREMELY short period, I DO NOT leave it. For safety reasons, use house wire for house and car wire for car.

building codes aside, stranded wire is most commonly used because of its flexibility compared to its equivalent solid core wire. that's why it is used mostly in cars because of the tight quarters it needs to be applied to. if flexibility isnt an issue, use solid wire. electronically, there really is no difference as long as you use the appropriate gauge wire for the length of the run from the source. and stranded wire has a tendency to heat up easier than the same gauge solid wire so if you are powering something that is going to be on a lot you might consider buying some solid core wire just for that reason.

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Yes it will work. But do not do this. It's not approved by the code (NEC) and your local building code inspector.

yeah, Im an electrican seen that done before. the outcome was not good for the owner of the home owner.

I'll cover all the bases here in one step.

Reason 1. The insulation rating of the speaker cable wiring is way different than romax. In short the speaker cable will burn fast if it’s over loaded. If there is a surge on the line or load side of the power you might have a fire. If your thinking of conduit emt metal or schedule 40 or 80 samething will happen. Last but not least speaker wire underground for power, the insulation will rot in or outside a conduit. then you will get jolted yourself from transit voltage walking by.



Use 14ga or 12ga romax. Outside lights should be wired to a ground fault protection circuit. ( GFCI )

vader beat me to it.

Wire is wire is wire is wire. Stranded, solid, Litz, varnished, cambric, THHN, lamp cord, speaker wire... Whatever. It all does exactly the same thing - EXACTLY. Conduct current from source to load. As vader says... Can it be done? Yes. SHOULD it be done? No. This being said, *IF* you find a spool of wire, that is labeled "speaker" wire, but it has a proper house insulation on it, (THHN, or similar) then it would be perfectly safe to use, that is *IF* it is insulated and installed correctly, per NEC rules.

Also referring to soundnsecurity's answer - As long as the wire is rated for the load it is carrying, then there is ZERO difference, electrically speaking. The resistance of a 12G stranded wire is the same or possibly slightly lower than an equally sized solid wire.

soundnsecurity, you are wrong, however about the "faster" or "more" heating of stranded versus solid wire. The stranded wire has more surface area per conductor gauge, allowing negligibly, but mathematically provably better cooling for a given gauge. Solid wire is less expensive, this is one of the major reasons for its use in construction. (I personally use stranded wire in everything I build, for this very reason. (Really, it's because I hate pulling solid wire...) I also install at least one gauge larger than is required, simply because overkill is a good place to start...)

As far as the flexibility issue, it is also rigidly connected to the building structure, either via staples or within conduit, but wherever there is any chance of a continuous vibration or movement, (think "power tool" (commercial table saw or band saw) on a "whip" - a flex conduit) stranded will always be recommended.

Back to the OP, though... The difference is in the insulation, and this is what the insurance company will take into account in any investigation. I wouldn't do it. I mean *I* would, for exceptionally temporary purposes, but I would most strenuously and very HIGHLY recommend you NOT do so.