Loudspeaker cone repair

Discussion in 'General Electronics Chat' started by praondevou, Feb 3, 2013.

  1. praondevou

    Thread Starter AAC Fanatic!

    Jul 9, 2011
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    Does anybody have experience repairing loudspeaker cones? I've seen some youtube videos but they only show slightly damaged cones. My speaker in the below picture is heavily damaged.
    Does anybody have tips how to repair this successfully or is it not worth it?

    [​IMG]
     
  2. MrChips

    Moderator

    Oct 2, 2009
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    Yes, I have repaired a 15" speaker and it is perfectly doable.
    You can buy the cone and the speaker cap (dome) separately or you can buy a repair kit that includes all you need including the cement and instructions.

    Procedure is fairly straight forward, only requires time and patience.
    First step is to get a sharp X-ACTO knife and cut away the cone.

    Edit: Oops. Sorry. Now I recall replacing the outer foam support ring only.
    In your case, I would attempt to glue the torn cone back together.
    I am sure you can get a replacement cone and cap if you want to do the whole thing, just a bit trickier.
     
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  3. mtroy1369

    New Member

    Jul 21, 2011
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    Hello,
    I have only been working on restoring tube radios for less than a year.
    But, I have had some success with the paper from tea bags or coffee filter cut to the size needed and glued with elmers glue.
    I was surpiised that no one had responded to your post??
    Hope this helps!!
    Matt
     
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  4. Audioguru

    New Member

    Dec 20, 2007
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    The speaker appears to have a very cheap "foam" surround that rots away in about 10 or 15 years. Good speakers have a butyl real rubber surround that stay flexible and lasts "forever". The cheap basket has only 4 screw holes.
    I betcha the large center dome is fake and covers a much smaller voice coil diameter.
     
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  5. praondevou

    Thread Starter AAC Fanatic!

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    All your assumptions are correct. However, the foam surround is perfectly ok for now.

    If I get it repaired for a fraction of the price of a new speaker I'll try it.

    Thanks all.
     
  6. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    I've seen them patched with the very light weave (1oz) fiberglass cloth and very, very thin layer of of epoxy.

    If you put too much weight on one side, the extra mass will result in the voice coil brushing the magnet from trying to accelerate it.

    If the speaker won't be used for high power/excursion, or midrange, it should work fine. For a speaker that is for higher power apps, a new speaker is a solution.
     
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  7. Audioguru

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    A replacement for the cheap speaker costs almost nothing in Canada.
    Most people in Canada have a pretty good income, even students.
    A better speaker costs a little more but many cost the same as the cheap one.
     
  8. THE_RB

    AAC Fanatic!

    Feb 11, 2008
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    That's a nasty tear! If you can get the tear edges to line up, you can repair it with quick drying nail varnish (acrylic top coat is good). Just paint it on as a line over the tear, about 6-9mm width.

    For the dimpled dome, prick a pinhole, then insert a fine wire hook bent to 90 degrees, and pop it back out. Then a dab of nail varnish on the pinhole.

    Or, you can buy a new 12" speaker of similar quality for about $25 from a supplier that sells to the repair industry.
     
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  9. bountyhunter

    Well-Known Member

    Sep 7, 2009
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    You can just use Gorilla Glue (urethane glue) on the cracks if all you want is to kluge it together. Considering the speaker quality, the sound probably won't change much. You could also cut thin strips of cloth like from a T shirt and soak them in glue and lay them over the tears as re enforcement for strength.
     
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  10. praondevou

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    I have all kinds of glue, that will be cheaper.
     
  11. praondevou

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    By the way, it may look cheap, but it makes some nice boom, no audible distortion etc. I think it's worth trying to repair it .

    Even if a new speaker costs next to "nothing"... save a dollar here and there and you always have money.
     
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  12. Audioguru

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    A cheap woofer has a strong resonance that makes a one note BOOM sound.
    A good woofer does not BOOM, instead it reproduces all the notes of music at the same level.

    A cheap woofer has a small magnet.
    A good woofer has a pretty big magnet.
     
  13. praondevou

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    LOL. I meant it has a good bass sound according to the music, not that it resonates for an hour after I turned off the music. ;)
     
  14. Audioguru

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    Maybe you have not heard a good speaker. You heard a cheap boomy speaker.
     
  15. thatoneguy

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    A lot of that depends on the enclosure. When they are tuned for 35Hz, there is a big non-linearity in flat response.

    I myself prefer a speaker that follows the input, rather than modifying it. The problem is it's more expensive since it takes a lot more electrical power to get the same perceived audio power at low frequencies (unless you use a tuned enclosure and load it by putting it in a corner of the house).
     
  16. praondevou

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    Ok, I'm not an audiophile, that's true. I never had the chance and would never buy boxes that cost a few thousand dollars...

    Especially not because all my music is now on a computer, mp3 encoded between 128kbps and 320kbps. They wouldn't sound different on a great sound system.

    A great sound system also almost forces you to take the time and listen to it and appreciate the wonderful sound. I have other stuff to do. :) Like repairing cheap speakers.
     
  17. Audioguru

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    Some people do not listen to music because they are deaf to the high frequency harmonics.
    Other people cannot hear differences in frequency then everything sounds the same.

    Some people do many things while listening to a great sound system.
    Especially women who can do more than one thing at a time. Guys can do only one thing at a time.
     
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