Electrical 12/2 wiring for speakers?

Discussion in 'Archived Threads 2001-2004' started by Mickey Brown, Jan 24, 2002.

  1. Mickey Brown

    Mickey Brown Stunt Coordinator

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    So I am refinishing my basement, running 12/2 electric wire everwhere. I was thinking to myself 'I wonder if this would make good speaker wire' since it's solid 12 guage copper wire. And it's cheap.

    Just wondering. I know people make speaker wire out of cat5 computer cable....
     
  2. John S Smith

    John S Smith Agent

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    Mickey

    I've posted this same question in several forums and never got a straight answer, to me a conductor is just that and unless someone can prove otherwise the effectiveness of the conductor should be it's resistance, measured in ohms. No?

    I am currently rewiring for a new HT and intend to run both 12 ga HD speaker wire (this forums economy wire of choice) AND regular 12 ga electrical wire in 1/2" conduit.

    After testing I will post my findings.

    ..john

    Ps I would run conduit, this leaves all your options open, good luck.
     
  3. Chu Gai

    Chu Gai Lead Actor

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    although solid and cheap, its very difficult to work with. as to it being sonically different from a similar length of stranded 12 gauge...nope, no reason why it should be.

    Good quality speaker cable should:

    have a total conductor cross-sectional area equivalent to AWG 12 gauge or heavier for long long runs

    be multi-stranded (100+ strands) for good handling

    flexibility

    have a hard wearing sheath, which is easily stripped back at

    the point of connection

    have one conductor easily distinguishable from the other by

    some sort of obvious marker.

    if you're running it in your walls, make sure the cable meets your local code.
     
  4. Ken Smith

    Ken Smith Stunt Coordinator

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    If I remember correctly you only need 12 guage for 20 amp circuits. If you have 15 amp circuits which is more common, you only need 14 guage. Both these types of cables are way too stiff for a good audio or speaker cable IMO.
     
  5. Bob McElfresh

    Bob McElfresh Producer

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    Micky, John, et. al: Wire does have resistance in ohms.

    But resistance is a DC phenomon.

    When you start sending a signal (varying with time), you discover new issues like Capacitance and Inductance.

    So for a fixed-frequency signal, the wire will react some way. When you change the frequency, the wire will do something a bit different.

    When you quickly change from one frequency to another, you get new issues called Dynamic Capacitance and ... (cant remember the one for Inductance, but there is an effect).

    Speaker wires have to handle sudden changes from 20 to 20,000 hz, and often many different frequencies at the same time. Power wire only has to carry a single 60 hz signal and current.

    So yes, they are both wires, but what you want to do with them (the type of signal you push down them) is very simple in one case, and rather complex in another.

    From a more practical side, the power wire was designed to be un-rolled, installed and never-moved for 10-30 years. Speaker wire is designed to be more flexable.

    Power wires are solid-copper wires for the current-handling ability. Speaker wires are stranded copper to increase the effective surface area for signal transmission (and to solve some of the impedence/capacitance issues).

    And do you really want to install and use the exact same wire for both AC power (which can kill you) and for speaker wire which you can casually strip and wire up with bare hands? Sounds like a bit of an accident waiting to happen to a loved one.

    Does this help explain why you should not use AC power wires for speaker wire?
     
  6. Bob McElfresh

    Bob McElfresh Producer

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    I just re-read my last paragraph and boy did it sound snotty. I apologize. :b

    I just dont think you should use something intended for one use (power wire) for something different (speakers).

    It's like when my wife bragged that when she was younger and had to change her own bike tires she used kitchen spoons to lever the tire off the rim rather than fancy tire-irons designed for the purpose. Sure it worked, but it's just ... WRONG.

    John: I just read your post more carefully and I strongly advise you to not run power wires in the same conduit as speaker wires.

    First, I believe (from reading another post) that this is a NEC violation, likely a fire-code and builidng code violation to run low-voltage wire in the same raceway as power wires.

    Second, That power wire will generate a small interference field whenever it is being used/running power. Any wire running near it will pick up some signal. The more parallel, and longer they are together, the more signal will be induced in the second wire. This can give you a very noticible 60 hz humm in those speaker wires when they are not carrying other signals.

    (You will also inject audio signals into the power wire when the speakers are being used, but this is not usually a problem.)

    Run the speaker wires at least 12" away from the power wires.
     

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