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Thread: New 2405 JBL Diaphragms - Are these bad? Pictrues - 1

  1. #16
    Senior Member Lee in Montreal's Avatar
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    US-made prices
    Third world assembly quality

    Hmmm....

  2. #17
    Senior Member Guido's Avatar
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    Looks like a US-Mexican cooperation.

    I had sooo many problems with bad cone kits that I'll not try diaphragms. No No

  3. #18
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    I'll try to attach pics.
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  4. #19
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    This pic and the previous 5 are of the first diaphragm.

    Kapton tape, with a tiny piece of styrofoam dust, not the lead. You can make this tape wrinkle out in the first pic of the first set of pictures.
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  5. #20
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    Here's the pics of the second diaphragm. These pics are fairly high magnification, so what might look like a huge hump in the Kapton is really fairly small.

    I've included the point of a needle in these pics to give some scale of the Kapton tape issue, and would like feedback from other members as to the severity of this Kapton issue in regards to sound quality. It's almost invisible to the naked eye, but I don't want to appear to be trying to put one over on anybody.
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  6. #21
    Senior Member edgewound's Avatar
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    What might look like a flaw under such magnification might be nothing at all. The definitive test is to install the thing, sweep it and listen to it.

    The voice coil/diaphragm are at such miniscule excursion at these frequencies that making contact with the top plate and creating a buzz probably won't happen. Most importantly, all the packaging styrofoam debris needs to be blown or dusted off the voice coil to make sure it's clean....and round with no high voice coil windings to rub in the gap.

    A competent technician might be able to clean up any possible production flaws....but really shouldn't have to....if you know what I mean.
    Edgewound...JBL Pro Authorized...since 1988
    Upland Loudspeaker Service, Upland, CA

  7. #22
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    You're right, no doubt. Now that I think about it, I probably should have inspected these more closely before offering them for sale. There shouldn't be such egregious flaws in these things, so back in the drawer they go.

    But at least it was caught before any money changed hands, that's worth taking the pics.

  8. #23
    Senior Member Mike F's Avatar
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    Quote Originally Posted by JeffW View Post
    I'll sell you a pair of new good ones, several years old still in the boxes. Shoot me a PM.

    I only have one pair, they are Steve's if he wants them, so please don't clog my PM box asking if I have anymore.
    Are those American or Mexican?

  9. #24
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    They are American, purchased in '09. Apparently about the time they quit putting glue on the Kapton, but the windings are pretty much flawless.The only problem I had was posting super high magnification pics of things you can't see with the naked eye. Here's what they really look like. Basically one of the last near perfect pairs of D16R2405 to see the light of day. But no more, they won't be seeing the light of day or camera again.
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  10. #25
    Senior Member 1audiohack's Avatar
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    You know your not supposed to offer anything for sale without telling me first anyway. Would have saved you all the trouble.
    If we knew what the hell we were doing, we wouldn't call it research would we.

  11. #26
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    I swear I don't need this, I'll smash the dang things with a hammer.

  12. #27
    Senior Member 1audiohack's Avatar
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    What are you talking about? If I said something to aggravate you I really didn't intend to.
    If we knew what the hell we were doing, we wouldn't call it research would we.

  13. #28
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    Quote Originally Posted by 1audiohack View Post
    What are you talking about? If I said something to aggravate you I really didn't intend to.
    That wasn't aimed at you, dude. I was just frustrated that my efforts at trying to help the guy out were so fruitless. I didn't even care about the money, I just wanted to see him get his drivers going.

    No good deed goes unpunished and all that, you can have the diaphragms for free if you need a pair.

  14. #29
    Senior Member 1audiohack's Avatar
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    Thanks Jeff! I thought I lit a fire and didn't know how.

    It is amazing how the "No good deed" thing goes sometimes.

    All the best,
    Barry.
    If we knew what the hell we were doing, we wouldn't call it research would we.

  15. #30
    Senior Member maxwedge's Avatar
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    Close ups with hi-res always makes stuff look suspect when it really isn't.

    PS: We're not in Intel's clean room here dammit!

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