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Thread: crack on acoustic lens

  1. #1
    Senior Member pyonc's Avatar
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    Smile crack on acoustic lens

    Hi, everyone,

    I've just found one crack on the top left slant panel of the 2308 acoustic lens of my 4343 left speaker. Can anyone tell me whether such a crack
    any effect on the actual sound? Thanks for your kind comments in advance.

  2. #2
    Senior Member ratitifb's Avatar
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    Quote Originally Posted by pyonc View Post
    Hi, everyone,

    I've just found one crack on the top left slant panel of the 2308 acoustic lens of my 4343 left speaker. Can anyone tell me whether such a crack
    any effect on the actual sound? Thanks for your kind comments in advance.
    probably NO but without picture

  3. #3
    Senior Member pyonc's Avatar
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    Smile

    Quote Originally Posted by ratitifb View Post
    probably NO but without picture
    Thanks for your comment. Let me upload the pic for closer look.
    I just wonder how the acoustic lens affects the mid-high range sound of 4343 or other similar systems with them. Looks like some JBLers just take them away when listening to music!!!

  4. #4
    Administrator Mr. Widget's Avatar
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    Quote Originally Posted by pyonc View Post
    Looks like some JBLers just take them away when listening to music!!!
    Have you read all of the posts on this forum? It seems like many JBLers are deaf too.

    I haven't used 2307/2308s in decades, but back when I did, I gave it a try with and without... you definitely want them on.

    As to your worry about hearing a crack? I really doubt it, but a drop of styrene cement should fix the problem if you can get in there in a way that isn't visually obvious.


    Widget

  5. #5
    Senior Member pyonc's Avatar
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    Quote Originally Posted by Mr. Widget View Post
    Have you read all of the posts on this forum? It seems like many JBLers are deaf too.

    I haven't used 2307/2308s in decades, but back when I did, I gave it a try with and without... you definitely want them on.

    As to your worry about hearing a crack? I really doubt it, but a drop of styrene cement should fix the problem if you can get in there in a way that isn't visually obvious.


    Widget
    Thanks a lot for your kind comment and observation, Widget.
    I've uploaded the pic. for your look. How about it? Do you think the current crack is slight enought to be ignored or still needs to be fixed with a drop of styrene cement?
    Attached Images Attached Images  

  6. #6
    Senior Member ratitifb's Avatar
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    except cosmetic issue, ignore it

  7. #7
    Maron Horonzakz
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    Just place a piece of tape on both sides and forget about it,,Or get a replacement lenz,,From Jammin Jersey.

  8. #8
    Administrator Mr. Widget's Avatar
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    Quote Originally Posted by ratitifb View Post
    except cosmetic issue, ignore it
    Personally I'd go this route. If every other aspect of your speakers are mint, then I would keep an eye out for a replacement, but I wouldn't be in a hurry. If you can live with a scuff or a scratch then I really doubt this will be a problem.


    Widget

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    While probably unnecessary, maybe a drop of cyanoacrylate along the back edge (against the baffleboard where it won't show) to keep it from spreading due to vibration. The CA will wick into the crack toward the rear.

  10. #10
    Administrator Mr. Widget's Avatar
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    Quote Originally Posted by toddalin View Post
    While probably unnecessary, maybe a drop of cyanoacrylate along the back edge (against the baffleboard where it won't show) to keep it from spreading due to vibration. The CA will wick into the crack toward the rear.
    If you are going to do this, use a styrene solvent instead... it will melt the plastic back into a whole again. CA glue won't really adhere well to the plastic and if you drop the lens (it does happen) the CA glue joint will shatter. CA glue is very strong and often convenient, but if you ever need to undo a CA glue job, tap it with a hammer... the glue line will fail.

    I do agree with Todd's approach. I would use a needle applicator and apply one drop to the back on the underside and let it wick into the crack. The crack looks tight enough that it should glue together nicely with no clamping needed. You need to use a thin styrene glue to do this... typical model glue is thickened and will not wick.


    Widget

  11. #11
    Senior Member pyonc's Avatar
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    Quote Originally Posted by Mr. Widget View Post
    If you are going to do this, use a styrene solvent instead... it will melt the plastic back into a whole again. CA glue won't really adhere well to the plastic and if you drop the lens (it does happen) the CA glue joint will shatter. CA glue is very strong and often convenient, but if you ever need to undo a CA glue job, tap it with a hammer... the glue line will fail.

    I do agree with Todd's approach. I would use a needle applicator and apply one drop to the back on the underside and let it wick into the crack. The crack looks tight enough that it should glue together nicely with no clamping needed. You need to use a thin styrene glue to do this... typical model glue is thickened and will not wick.


    Widget
    Thanks for this kind instruction.
    In addition to fixing this one, I've decided to buy an original used pair as a reserve on ebay.

  12. #12
    Senior Member pyonc's Avatar
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    Quote Originally Posted by toddalin View Post
    While probably unnecessary, maybe a drop of cyanoacrylate along the back edge (against the baffleboard where it won't show) to keep it from spreading due to vibration. The CA will wick into the crack toward the rear.
    Thanks. Looks like the ca is very strong. I think I need to be cautious...

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