Converting a 16ohm speaker to an 8ohm speaker

Discussion in 'Amps and Cabs [BG]' started by patrickj, Feb 28, 2003.

  1. patrickj


    Aug 13, 2001
    Baltimore, MD
    How could this be done?

    For example, I have 2 10" drivers - exactly the same except for impedance. One is 16ohm, the 2nd is 8ohm. What would I need to do to rebuild the 16 as an 8? I'm assuming fewer/more windings on the voice coil?

  2. It could be done, but cost effectiveness, put the one you don't want on ebay and buy another. You'd have to send it in to be reconed to the impedence you wanted.

    Or you could hook them in parralell and I think you would either have 6 or 12 ohms, I can't remember.
  3. patrickj


    Aug 13, 2001
    Baltimore, MD
  4. Ehrr, do you really think you can wind a voice coil yourself? If you succeed, I have a few speakers I 'd like you to rewind for me ;)

    Seriously, even when a speaker is damaged and only the voice coil is burnt, you can't do anything but replace the complete cone/suspension/spider/coil system and most of the times the basket too, because of the simple fact that these parts are, without exception, glued together with high-temperature resistant glue.

  5. patrickj


    Aug 13, 2001
    Baltimore, MD

    I'll give it a try, let you know how it works.
  6. I repeat: do you really think you can wind a voice coil yourself? I have handled dozens of speakers, taken them apart, restored cones and dust caps, restored surrounds, repaired cone wires at best, but I have never rewound a voice coil. Believe me, if it were possible, I would have done it.

    You would have to disassemble the speaker to expose the voice coil, remove the old coil from the glue it is embedded in, find the correct diameter square enamelled copper or aluminium wire, put the new coil neatly in the exact same spot as the old one while allowing it to have the exact same dimensions, glue it (heat resistant) tight, hard solder it to the cone wires, re-assemble the speaker and not get a voice coil rub.

    It can't be done. If you can pull it off at all, the speaker will sound like a $10 radio shack junkbox part.
  7. BillyB_from_LZ

    BillyB_from_LZ Supporting Member

    Sep 7, 2000
    To answer your question...unless you recone it, you really can't change a 16 ohm speaker to 8 ohms.

    If you remove half of the turns from the voice coil, you might (repeat might) end up with an 8 ohm speaker. However you've altered the inductance of the coil which in turn affects impedance.

    The bigger problem is that a speaker's power rating is partially dependant on the maximum current rating that the coil can withstand without burning out. Without changing magnet wire sizes you'd at best cut the power rating in half since ohm's and watt's laws apply.

    And all the coil winding prowess in the world won't help if you destroy the cone/surround/spider etc. taking the speaker apart in the first place.

    So, you'd be wise to either recone the 16 ohm speaker with an 8 ohm kit, or sell the speaker and buy an 8 ohm unit.

    Depending on the brand, you might be able to buy a kit for the speaker and recone it yourself...which, if you're careful is a fairly easy procedure.

    Have fun...and good luck!!!!
  8. patrickj


    Aug 13, 2001
    Baltimore, MD
    It can't be done period, or it can't be done because it requires more time to pull it off than you've deemed necessary vs. buying a new one?

    I've built (and am building) basses, I'm winding pickups (learning), I've design and built bass cabinets, I've designed and built all of my effects.. I'm not adverse to trying something for the sake of experimenting and learning how to do it.. And I don't mind using my time for a project - even if it doesn't work in the end. I've still learned more by trying to accomplish the goal than not trying in the first place.

    As it is now, the speaker is junk to me. I have no use for it, nor do I for the forseeable future. I do have use for an 8ohm version of the same thing. Given enough patience, practice, and research before I start, why couldn't I pull it off?

    Regardless, thanks for your assistance.
  9. patrickj


    Aug 13, 2001
    Baltimore, MD
  10. Now we're talking, you sound like you've done your fair share of building stuff yourself... With that much experience you might pull it off, and I'd say just try it (cause who am I to stop you from doing it anyway?). BUT... chances are still small you end up with a usable speaker. The new coil WILL have different dimensions (you're using a different gauge of wire) and possibly a different weight. And I doubt you can affix it to the coil carrier the same way a winding robot can.

    What I'm saying is: it can't be done without seriously altering the Thiele/Small parameters of the speaker and thus rendering it practically useless, unless you have a meaurement setup to find the new T/S parameters. If you have a weekend to spare, go for it. I wouldn't.
  11. BTW, feel free to read chapter 6 of this article
  12. Petebass


    Dec 22, 2002
    QLD Australia
    I pulled appart a speaker out of an old Trace Elliot 2x10 that wasn't working. I had no need for it so disassempbed on of the speakers with no intention what so ever of putting it back together. It turned out to be one hell of a learning experience, opening up a can of worms and an insatuable appetite for all things audio and electronic. It also created a much better understanding of how speakers work and how they get damaged. I reckon everyone should do it once, even if it's with a really cheap no-name speaker.

    I say go for it! And let us know how you go.