Speaker Wire Polarity Tester

Discussion in 'Audio Hardware' started by rstamberg, Apr 9, 2008.

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  1. rstamberg

    rstamberg Senior Member Thread Starter

    Location:
    Riverside, CT
    Is there such a thing? I need to check my speaker wires for polarity (they run through walls and are unmarked). You know, right (red) wire/left (black) wire ... It's way too much trying to figure it all out with a polarity-check CD ... I'm wondering if there's an instrument that'll tell me. Does something like this even exist? I'm kinda desperate.
     
  2. alanb

    alanb Forum Resident

    9 volt battery -- has a positive and a negative- right.
    other end-- volt meter--can see positive or negative voltage--easy.
    You got a volt meter?
     
  3. R. Totale

    R. Totale The Voice of Reason

    Put the two speakers as close to each other as possible (face to face is ideal), play something with bass, and try it both ways. The way where the bass doesn't disappear is the right one, so mark it.
     
  4. Mr X

    Mr X Forum Resident

    Location:
    NY, USA
    If your speakers are out of phase, you will have a noticeable lack of bass. Try switching the wires to one speaker and it should be obvious which way the polarity is the same for both speakers.
     
  5. alanb

    alanb Forum Resident

    No volt meter.
    Connect a flash light bulb to one lead and run another wire outside the wall between the bulb and the battery-- then connect ONE wire from the speaker wire to the bulb-- the one that lights the bulb is the one connected to the battery at the other end.
     
  6. Doug Sclar

    Doug Sclar Forum Legend

    Location:
    The OC
    Very easy to do. First of all you can use your ears, but even easier is to use a small 1.5 volt battery. Hook the speakers up randomly and then hook the battery up to the leads on the other end of the wires. Depending on which way you hook the battery up, your woofers will either move in or out.

    In other words if you reverse the wires at the battery end you will clearly see the difference. As long as you get both speaker to move the same way you are good for relative polarity, but not necessarily for absolute polarity.

    Generally the speakers will move forward with the plus terminal of the battery on the right lead. This lead should hook up to the positive output of the amplifier, and the other lead should be hooked up to the low output, generally but not always ground.
     
  7. Glen B

    Glen B New Member

    Location:
    USA
  8. Ray Blend

    Ray Blend One and Two

    Location:
    The Midwest
    also comes in handy for checking true polarity (speaker and cable).
     
  9. Doug Sclar

    Doug Sclar Forum Legend

    Location:
    The OC
    The battery is the easiest and the cheapest.

    I've done large arrays of speakers in series parallel configurations where you can't easily tell by looking at the wires. Take off the grilles hook up your battery and you'll instantly tell if they're all moving the same way or not. What could be easier?
     
  10. Glen B

    Glen B New Member

    Location:
    USA
    The OP did not state where the wires originate and end. If they are very close, no problem with a battery -- I've used one many times to check polarity. If the wires are run inside the walls and the ends of the wires are far apart where you can't see cone movement, using a battery becomes more difficult.
     
  11. Doug Sclar

    Doug Sclar Forum Legend

    Location:
    The OC
    Yes, good point.

    But you can leave the battery hooked up and visit the speaker. You can usually tell if it is sucked in or pushed out. Of course this will eat the battery in short order.
     
  12. Mike from NYC

    Mike from NYC Forum Resident

    Location:
    Surprise, AZ
    Not only is the bass minimized the imaging is also affected. I found this out when my monitor at work was replaced and they reversed the wires. Instead of a nice centered image the image was coming from the sides of the speakers. It screwed up my head a bit until I figured out the problem.

    BTW, do you think I need to burn in my new computer to get the best possible sound?
     
  13. alanb

    alanb Forum Resident

    Absolutely....the fastest way would be to play music 24x7 for a week or 2.:)
     
  14. JBStephens

    JBStephens I don't "like", "share", "tweet", or CARE. In Memoriam

    Location:
    South Mountain, NC
    About absolute polarity, for those wondering - the initial attack of a waveform coming out of a speaker should be a crest, not a trough, just as it would be in nature. A compression, not a rarefaction. Sometimes that's hard to maintain at the ear, since there are so many points in the recording chain where polarity reversal can occur, you never know if the recording itself is the correct absolute polarity. Just do a search on "absolute polarity" and you'll come up with lots of things. And it really does make a difference.
     
  15. Doug Sclar

    Doug Sclar Forum Legend

    Location:
    The OC
    Speaking as a former engineer, I'll say that for the most part there is no such thing as absolute polarity in multitrack pop recordings. There are so many places where phase can be inverted that many engineers rarely paid much attention. Sure relative polarity is a factor when corellated mics are used. But for single channel inputs and overdubs, it's usually just hit and miss.

    Now if you're talking about a classical recording made with two microphones, than yes it is most definitely something you may want to pay attention to.
     
  16. rstamberg

    rstamberg Senior Member Thread Starter

    Location:
    Riverside, CT
    Thanks for all the replies, everyone.

    The battery and the meter look like the best way for me to go.

    BTW, someone told me NOT to use a 9.5 volt battery to test the woofer position as leaving it hooked up for more than a second can damage the speaker ... true?
     
  17. MusicMtnMonkey

    MusicMtnMonkey New Member

    Location:
    Vail, CO, USA
    Did anyone mention the toner? If you have a wire going through walls and you're trying to verify where it ends up specifically use a toner. It is a sender and reciever you hook to a wire without audio equipment attached. The reciever can "hear" the tone on the wire it's attached to on the other end. I don't know if it will help as much with audio. But say if you have a phone outlet in a room and a bundle of like 10 phone wires somewhere else, you have no idea which one is the phone line to the room. Attach the toner and find the wire that makes the sound.
     
  18. Doug Sclar

    Doug Sclar Forum Legend

    Location:
    The OC
    I use toners all the time, but they won't help with polarity unless you get one of the advanced models.
     
  19. Doug Sclar

    Doug Sclar Forum Legend

    Location:
    The OC
    I'd use a lower voltage battery, but I've used a 9v before with no problems. But it will get hot and fail quicker as it generally has less current. If you do the math, 9v would only deliver about 10 watts to an 8 ohm speaker, which is not generally enough to damage a woofer.

    I've actually used 18v batteries before from a DeWalt cordless drill and have never damaged a speaker.
     
  20. Jim G.

    Jim G. Geezer with a nice stereo!

    Your question is confusing. For a stereo pair of wires there are four wires. A +left, a -left , a +right, and a -right. if wires were colored red, black. That is, two red wires and two black wires they would be arrainged as one red black pair for one speaker, and one red black pair for the other speaker. thus polarity would be obvious, red +, black -. however if all you have is two red wires and two black wires , then your problem is not polarity, it is pair matching. You need to state your situation exactly. What do you have at each end of the wire runs? Almost all wires are marked for polarity, sometimes hard to see, but there.
     
  21. Mr X

    Mr X Forum Resident

    Location:
    NY, USA
    For some reason, I find it amusing that on a forum where every other member can hear the difference between 100-strand power cables and 101-strand power cables (ok, I exaggerate), that so many are recommending equipment to detect in-phase spreakers. If you can't hear the difference between in-phase and out of phase speakers, there's hardly any point even coming to this site.
     
  22. rstamberg

    rstamberg Senior Member Thread Starter

    Location:
    Riverside, CT
    Thanks, pal. I won't come back.
     
  23. rstamberg

    rstamberg Senior Member Thread Starter

    Location:
    Riverside, CT
    You are correct ... except there are wires for a couple of speakers that do not seem to have any marking whatsoever. Truly. I am connecting one "red" and one "black" (or one positive and one negative, if you like) per speaker. Simply put, I need to be sure the wires connect to the "red" and "black" inputs on each speaker correctly. Am I clear yet? Maybe polarity was the wrong word.
     
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