# can you run 120v along side speaker wire?



## methcat

iv'e got an old house on slab witha ll open beam ceilings... kinda makes it tough to hide anything. i'm planning on running my rears in a hidden track along the center beam along my ceiling, is there any type of speaker wire that would be safe to run along side 120V ac that powers a couple pendant lights? (no transformers involved here...)


thanks for any help,


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## Targus

Speaker cables aren't susceptable to induced hum, due to the low impedance of the circuit.


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## methcat

thanks, much appreciated...


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## AV Doogie

Signal or data cabling should always be run separately from power. Makes life safe and easy.


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## methcat

nope, just rear channel output...


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## trekguy

Yes, no, sometimes.


In general it is a good practice not to run low voltage and signal cable alongside power cables. Hum is not the only extraneous signal that you can pickup and there is always the odd chance of an accident delivering 120 to your inputs.


Can it happen. Yes. I've had the unpleasant experience of turning on a PC an watching the surge protector and then the PC go up in smoke. The 120v circuits shared a chase with network cable and a lighting circuit. The lighting circuit wiring failed mechanically and delivered an over-voltage to a 120 circuit and to the CAT 3 network cable--no circuit breaker tripped in either the lighting circut or the 120 service to the cubes. The over-voltage on the network connection fryed a board in the server. *No one was killed*.


Having said that, a twisted pair of speaker wires will avoid most stray signals, but lateral separation is best.


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## Targus




> Quote:
> a twisted pair of speaker wires will avoid most stray signals,



So will having an ~8 Ohm impedance.


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## trekguy




> Quote:
> Originally Posted by *Targus* /forum/post/0
> 
> 
> So will having an ~8 Ohm impedance.



You are correct, sir. I didn't intend to imply that you were in error. But for the belt and suspenders brigade...


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## methcat

i came across these websites, they seem to say that it's a real no no. does anyone have any real experience comming across this?

http://www.crutchfieldadvisor.com/S-...it.html?page=3 

Don't run it close to power cables this can negatively affect the sound. (You can find out where the power cables are in your home by exploring nearby crawlspaces, or possibly by obtaining a copy of the electrical plan from your builder.) Don't let speaker wire and AC power cable run parallel for more than 5 feet. If they do, keep them a minimum of 12 inches apart, but preferably at least 2-3 feet apart. If they cross paths, keep them at 90-degree angles.

http://www.hometoys.com/htinews/feb9.../wg_route.html 

Routing Around Electrical:

The main thing to watch in routing low-voltage signal cable is avoiding high-voltage AC wiring. It is OK to cross low voltage signal and speaker wires at 90 degrees to electrical wiring (cross perpendicularly), but avoid running parallel and close to electrical wiring. This will cause noise in speakers (at low volumes) and could cause data errors in data lines. Everyone told us to do the low-voltage wiring after the electrician has finished his pre-wire! I heard several "horror stories" about running speaker wires then later finding the electrician liked the holes that had already been drilled, and used the speaker wire holes for his electrical wire. One installer even drilled holes through many joists to get a path, went back to where he started the holes, and found the electrician filling his new holes with electrical runs. If you do any wiring on outside walls, make sure you do it before insulation!


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## Targus




> Quote:
> does anyone have any real experience comming across this?



Yes, and we already responded.



> Quote:
> This will cause noise in speakers (at low volumes)



This is incorrect.


None of your links mention circuit impedance...it's almost as if they don't know what it is.


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## methcat




> Quote:
> Originally Posted by *Targus* /forum/post/0
> 
> 
> Yes, and we already responded.



i'm sorry, i guess i meant "was there some rare circumstance where someone has experienced noise?". i appreciate your help so far, i was just second guessing myself after i had seen web pages like this, especially on sites like crutchfield (not that they are electricians or anything)


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## indil377




> Quote:
> Originally Posted by *trekguy* /forum/post/0
> 
> 
> Yes, no, sometimes.
> 
> 
> In general it is a good practice not to run low voltage and signal cable alongside power cables. Hum is not the only extraneous signal that you can pickup and there is always the odd chance of an accident delivering 120 to your inputs.
> 
> 
> Can it happen. Yes. I've had the unpleasant experience of turning on a PC an watching the surge protector and then the PC go up in smoke. The 120v circuits shared a chase with network cable and a lighting circuit. The lighting circuit wiring failed mechanically and delivered an over-voltage to a 120 circuit and to the CAT 3 network cable--no circuit breaker tripped in either the lighting circut or the 120 service to the cubes. The over-voltage on the network connection fryed a board in the server. *No one was killed*.
> 
> 
> Having said that, a twisted pair of speaker wires will avoid most stray signals, but lateral separation is best.



How did the voltage get onto the Cat-3?


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## trekguy

I misspoke.







All of the wiring, including the network cable was was burned, but I don't actually know that there was a short _to_ the network cable.


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## wickidweasel

mine are running with 240v no problems


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## Chu Gai

If you're really unsure, do your own experiment with an extension cord hooked up to something like a table lamp. Run the cord parallel, perpendicular, wrap it around your speaker wires, and determine for yourself what you hear or don't hear.


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## methcat




> Quote:
> Originally Posted by *Chu Gai* /forum/post/0
> 
> 
> If you're really unsure, do your own experiment with an extension cord hooked up to something like a table lamp. Run the cord parallel, perpendicular, wrap it around your speaker wires, and determine for yourself what you hear or don't hear.



not sure why i didn't think of that before... good idea.


thanks all.


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## NightHawk

An even easier way to convince yourself is to take a set of headphones, which have a higher impedance than loudspeakers, and wrap the otherwise unconnected headphone cord around your dryer or electric range power cord several times. This will duplicate the worst possible case. You will hear nothing in the headphones.


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## Chu Gai

Of course, if you don't hear it, you'll be branded as unable to detect subtle nuanaces such as darkness, pace, rhythm, timing, soundstage, location, palpability, definition, air, delineation, and all that other good stuff.


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## JeffStickney

Household power cycles at 60 hz. That frequency is really to low and slow to worry about crosstalk.


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## Targus




> Quote:
> Originally Posted by *JeffStickney* /forum/post/0
> 
> 
> Household power cycles at 60 hz. That frequency is really to low and slow to worry about crosstalk.


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## djearl81

methcat -


If you run them next to each other you'll increase the chances of having an issue. You'll probably hear a pop when you turn the system on or off. At the end of the day it's your call. You could debate both sides for a long time.


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## Targus




> Quote:
> You could debate both sides for a long time.



...or, you could learn about impedance.


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