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Single speaker out of phase?

Discussion in 'Amps and Cabs [BG]' started by lastnerve, Aug 27, 2012.


  1. lastnerve

    lastnerve

    Jan 27, 2012
    Can a cab with a single 18" speaker (our sub-woofer) be wired out of phase? We recently had to replace the input jack and in the process accidentally pulled the connectors off the speaker. There are no markings on the speakers connectors to tell us which is pos or neg.
     
  2. M.Mannix3

    M.Mannix3

    Jun 12, 2010
    I'm no expert but I believe out of phase when talking about speakers only happens when you have 2 or more speakers.

    I think speakers are not polarized so it should be able to go on either way
     
  3. yes it can! If you solder the tip wire to the sleeve and the sleeve wire to the tip it will be out of phase.
     
  4. a way to find out is with a battery, take a wire and conect the tip to the + of the battery and with another wire the sleeve to the -. If the speaker membrane moves to the front it´s in phase, if it moves backward it´s out of phase.
     
  5. lastnerve

    lastnerve

    Jan 27, 2012
    Okay, but I guess my question should have been "will a single speaker sound any different when it's out of phase?"
     
  6. well yes it sounds different but it´s hard to say. The speaker is meant/constructed to work in phase.

    You may have problems in conjunction with other speaker, like when you play with PA support....
     
  7. lastnerve

    lastnerve

    Jan 27, 2012
    I'll try the battery test to make sure it's in phase. We tested the cab already with the connections both ways, but we couldn't discern any difference. However, as you said, it's meant to be in phase so it's best if we ensure that it is.

    Thanks for the help.
     
  8. wcriley

    wcriley

    Apr 5, 2010
    Western PA
    Very few people even claim to be able to hear differences in absolute phase. Maybe on the order of 1 in a million?

    ??????

    The distance between the bass cab and the PA sub will cause just as many phase problems as the bass cab being wired with reverse polarity.
     
  9. dincz

    dincz

    Sep 25, 2010
    Czech Republic
    Total nonsense alert! There's only one speaker. What is it out of phase with?

    Polarity can be reversed but it won't sound any different.
     
  10. majortoby

    majortoby

    Jul 2, 2009
    Tampa, Fl USA
    Dude. Disregard this thread. Wire the speaker up, and use your damn ears, lol. Ask TB how to tie your shoes, and 30% of the responses will be people criticizing your choice in shoes, with another 25% claiming no shoes is superior, and another 45% will provide anecdotes about how their shoes treated them 5 decades ago........my point being: Although I appreciate the desire to be armed with all the knowledge you can, I think TB will over-think this to the point of COMPLETELY obfuscating your end goal. Wire it up, if it sounds great, gratz...if not, reverse the wiring, and call it a day!
     
  11. bassman1nh

    bassman1nh Banned

    Aug 27, 2012
    Out of phase with respect to what? Phase is relative. Not sure absolute phase is relevant here, but it might be. If you bang on the strings should the initial impact of hitting the strings move the speaker cone out or in - absolute phase wise? Would guess that the impact of hitting the strings should move the speaker cone out initially creating an leading-edge high-pressure wave much as a correct absolute phase recording of a gunshot or cannon firing should result in an initial high-pressure wave same as the original source. Is there a standard for bass? Does absolute phase really matter at all for bass?
     
  12. majortoby

    majortoby

    Jul 2, 2009
    Tampa, Fl USA
    See what I mean? Step away from the keyboard and heat up your iron....
     
  13. Someone close to having a clue, good for you.
    The initial peak should be with forward cone movement. Reason is if you are running close to Xlim you don't want your strongest peak to drive the voice coil of the speaker into the magnet structure.
    Out of phase can ONLY happen when to driver is played with any other speaker producing the same frequency band.
     
  14. georgestrings

    georgestrings Banned

    Nov 5, 2005
    +1... and will add that if it were me, I'd battery test to determine proper speaker *polarity*, mark the positive terminal, and wire accordingly...

    Another good reason for doing this is that it will also be more likely to be "in phase" with another cab, should you ever pair it up with one - there is certainly no valid reason to run a speaker in reverse polarity, even though it will work that way...


    - georgestrings
     
  15. and don't pluck hard on the up stroke:ninja:
     
  16. Doesn't matter. The next waveform will be identical anyway. Besides, how would you know if your bass is in phase? All of your preamp stages? Pedals? The power amp?

    It's ONLY relevant when combining a speaker with another speaker.
     
  17. As you know, normally the tip of the jack goes to the (+) on the speaker and the sleeve to the (-), but since the speaker isn’t marked (assuming you stay within your amp load) you could stack another correctly wired cab on top of that cab and make sure both speakers move inward and outward together - if not, you know you have the (+) and (-) backwards on that cab.
     
  18. As I said, phase is only relevant when another driver shares the same frequency band (in case you missed that part?)
    The positive and negative are identified on most speakers for the reasons I stated. What happens in the signal chain can agree with this "polarizing" or make it futile. ;)
     
  19. I was addressing the part of your post which I quoted.
     
  20. rickdog

    rickdog Gold Supporting Member

    Mar 27, 2010
    Yes, the subwoofer can be out of phase with the other speakers. Depending on the crossover (if any), the frequency and phase response of the various cabinets, and effects due to speaker placement and room resonance, this may or may not be noticeable.

    If I were in this situation, I'd use a 9V battery to determine the + terminal on the speaker (cone moves out when the + terminal of speaker is connected to + on the battery), wire that one to the tip on the jack (phone jack; 1+ if it's a Speakon), and not worry about it further.
     

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