speaker cables running with AC lines

[rabbit_ears]

I'm looking to put some in-ceiling speakers in my kitchen and some outdoor speakers outside runing off the second and third zone of my Onkyo 805. the problem is the only way i can run the speakers over to that side of the house is drop them through the floor and pull them across in the same joist space that i'm using to pull AC wire for additional circuits in the kitchen. i don't have much choice all wall and ceilings (including the basement) are finished drywall. what are the chances that i will pick some sort of harmonic interference from the AC lines? is there anything i can do to minimize or eliminate it?
second question can i put volume controls in the same j-box as light switches?
if it helps or matters speaker wire runs will be approximately 30' (but i can spearate from AC after about 10').
Any advice based on personal experience would be great. i've had guys at the local stores tell me it doesn't matter (but one of them also told me i had to run a separate impedance matching volume controller for every pair of speakers too). I've read that i should keep the speaker wires 1ft away from AC and cross at 90° where ever possible and i would do that if i were working in new construction but i'm not. Please help.

 

[Rickster71]

The advice to keep away from AC and cross at 90° where ever possible, is sound advice.
Try to do it that way, as best you can. Can you keep them at opposite sides of the joist bay?
Possibly add a few 2 x 4 studs as a shield between the two types of wires in the bay.
Are your speaker wires going through the same hole as your AC wires?
Most of the time, a zones 2 and 3 aren't critical listen areas anyway, so give it a shot. From your description, it sounds like options are limited.
To answer your second question:
No, you cannot mix high and low voltage in the same J-box. It's against code.
Though they do make boxes with approved dividers. There is a possible noise issue though.

 

[Johnd]

Why can't you shoot it through one or two joist spaces over? That would be my first recommendation...speaker wire is easy to run.

The other thing I'd recommend is if you have to run the speaker wire in the same bay as the electrical, is to connect the speaker and run it while drawing current through that electrical circuit prior to closing the ceiling. If you detect no emi, and both the speaker cable and electrical wires are in a fixed position, you should be ok.

Other than that, Rickster pretty well covered everything.

 

[bandphan]

what type of ac lines are existing? Most lines have to be in conduit, unless the home is older and romex was used. I have issues running video lines near ac conduit but not speaker wire(unless it headends to lcd type volume control) are you using cl rated? Ive seen prewire where an "electrican" ran speaker wire for a homeowner side by side.

 

[mtrycrafts]

IF you have no choice in the matter, use twisted pairs of speaker cable, as some do come like that. It has a greater rejection capability and keep it as far away from the AC as possible.

 

[Rickster71]

IF you have no choice in the matter, use twisted pairs of speaker cable, as some do come like that. It has a greater rejection capability and keep it as far away from the AC as possible.

Good Idea!

 

[rabbit_ears]

thanks for the tip. i plan on running two runs of 14-4 CL2 wires but i haven't seen any that are available twisted but if i twist these two sets together (ie stick free end of each in a drill and spin 'em) will that in effect do the same thing or do the twisted set have to be the same channel? and will the fact that i may or may not be using the 2nd zone at the same time as the 3rd or vice versa have any affect?

 

[Johnd]

but if i twist these two sets together (ie stick free end of each in a drill and spin 'em) will that in effect do the same thing or do the twisted set have to be the same channel?

ROFLMAO!!!

You're kidding right? If you're not, no, do not do this. You'll probably just end up stretching and shredding the insulation. And as if you've given this that much thought anyway, why would you need to stick each end of the wire in a drill to braid them. If you don't put one of the drills in reverse, you're stuck in an eternal exercise of futility! You understand that, don't you? Don't take offense to this paragraph...it is simply the plainness of my writing and my dry sense of humor at work again.

mtry's suggestion is out there. And that's good. Have you pondered the other suggestions proffered here?

 

[Rickster71]

thanks for the tip. i plan on running two runs of 14-4 CL2 wires but i haven't seen any that are available twisted but if i twist these two sets together (ie stick free end of each in a drill and spin 'em) will that in effect do the same thing or do the twisted set have to be the same channel? and will the fact that i may or may not be using the 2nd zone at the same time as the 3rd or vice versa have any affect?

14-4 CL2 or 14-2 both have twisted-pair conductors.

A lot of your potential noise, depends on the equipment on those circuits.
As long as they aren't feeding your refrigerator, microwave, AC unit.
IMHO, do it. If you run into too much noise, we can always do something with a ferrite core at the speakers.

 

[rabbit_ears]

John i don't know why you find this so funny. though i didn't really understand how twisting the speaker wires together would work as they would be acting as an antennae for any EMF and not the source but it doesn't cost anything to try it; beside it may make it easier to pull the wires and keep them straighter.
I twisted wired like this (in a drill) when running invisible fence for my dog (return run has to be twisted together to cancel out EMF), the in-floor radiant heating cables that i am using has twisted wires to eliminate EMF. while the concept may not work i don't think it's requires your rhetoric.

 

[Johnd]

John i don't know why you find this so funny. though i didn't really understand how twisting the speaker wires together would work as they would be acting as an antennae for any EMF and not the source but it doesn't cost anything to try it; beside it may make it easier to pull the wires and keep them straighter.
I twisted wired like this (in a drill) when running invisible fence for my dog (return run has to be twisted together to cancel out EMF), the in-floor radiant heating cables that i am using has twisted wires to eliminate EMF. while the concept may not work i don't think it's requires your rhetoric.

Well, I'm sorry you feel that way rabbit ears...but my post was not all rhetoric. We're not talking an electric fence here. So while you're explanation seems logical, it does not apply to speaker wiring (putting ends in a drill and...whirrrrrr ).

Do not allow my humor to undo my statement. I truly thought you were kidding...it just seems preposterous (for speaker wiring).

It's funny that I'm the only one here that directly answered your question: that has informed you not to do this, and you shoot me down. HMMM. Understand that I did answer your question. That's what this forum is about. Lighten up, and you'll have more fun and learn more here.

 

[Seth=L]

Unfortunately the only brand I can think of at the moment that sells twisted or braided speaker wire is Monster Cable. I am sure there is some cheaper alternative, i just haven't seen it.

 

[Johnd]

Unfortunately the only brand I can think of at the moment that sells twisted or braided speaker wire is Monster Cable. I am sure there is some cheaper alternative, i just haven't seen it.

Seth, Buddy. Where the heck have you been? Good to hear from you. You need to get over to the vent and answer some questions pronto!

Funny ha ha, btw.

 

[mtrycrafts]

Unfortunately the only brand I can think of at the moment that sells twisted or braided speaker wire is Monster Cable. I am sure there is some cheaper alternative, i just haven't seen it.

There are others that have the pairs twisted inside the insulation, somehting like CarolcoCarlon comes to mind, or something like that.

 

[mtrycrafts]

thanks for the tip. i plan on running two runs of 14-4 CL2 wires but i haven't seen any that are available twisted but if i twist these two sets together (ie stick free end of each in a drill and spin 'em) will that in effect do the same thing or do the twisted set have to be the same channel? and will the fact that i may or may not be using the 2nd zone at the same time as the 3rd or vice versa have any affect?

If the two wires inside the insulation is free to be twisted, not molded with the outside jacket, then by all means, try it.
Maybe you have an electronics parts store in your area that sell twisted 14-2.

 

[WmAx]

IF you have no choice in the matter, use twisted pairs of speaker cable, as some do come like that. It has a greater rejection capability and keep it as far away from the AC as possible.

By what principle does twisting a normal cable offer any substantial difference of rejection? From my understanding, twisting a cable reduces inductance. A benefit for digital data transmission wiring, of course. Twisting the cable also insures greater chance of equal noise injection of both leads - again beneficial where differential balanced line transmitters/receivers are involved. How does this increase rejection on a unbalanced line?

-Chris