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Thread: Large format alnico driver.

  1. #16
    Administrator Mr. Widget's Avatar
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    John,

    I don't know the answer to your question, but when I queried JBL about working on the 2441, they told me that they demag it before they work on it and implied that it easily came apart once the demag was done. I doubt you can completely demagnetize one without a very powerful electromagnet.

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  2. #17
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    Quote Originally Posted by scott fitlin
    I believe you are looking for the Hellfire club! They do spankings! We do woofing!

    Man, if I was on that thing, I'd be barfing......

  3. #18
    RE: Member when? subwoof's Avatar
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    I use (4) grade **8** 1/4-40 bolts that are tapered to a small flat surface in each of the horn mounting holes.

    Tighten each one down and then do a 1/8 ( or so ) turn on them one at a time and the top plate will lift off. Be sure to WD-40 the holes first in case you have to remove a snapped off bolt.

    If you use a bit of acetone down in the throat bottom it will soften the glue that holds the bakelite throat in place - this should prevent the screen from being deformed.

    Then use a succesion of wooden dowels to keep the parts apart until you can remove it by hand. Some of the later models used glue to hold the alignment ring in place and this sometimes is a super-tight fit to the phaseplug.

    BTW - watch the fingers on this...it will hurt.

  4. #19
    Charley Rummel
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    ....then, carefully put all the parts into a sturdy box, get an RMA number from JBL, and send it in for the pro's to work on...

    Sorry, I didn't mean to upset you. Good luck on your project. Please keep us all posted on how it goes. If possible, post pictures of your progress.

    Regards,
    Charley

  5. #20
    paragon
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    Magnet ?

    Parts are only fixed by the magnet ?? Is it ? So i have to be very carefull with my old 2441 !

    Eckhard

  6. #21
    Administrator Mr. Widget's Avatar
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    If they are dropped they are usually damaged by the magnet shifting and the throat cracking. Anyone interested in buying a 375, 376, 2440, 2441 etc. must look out for cracked throats. Many people do not realize that inside this 20+ lbs cast metal driver is a delicate plastic throat.

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  7. #22
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    Hi Subwoof So once the top plate lifts away from the casting ,does the casting just pull away??? Or is there still alot of magnetic pull to contend with???

  8. #23
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    alltec

    Hi John,
    It seems very interesting to break a JBL 2440 down to the parts.
    I want to see PICS~~~~

  9. #24
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    Here are the parts that make up the 2440.
    Attached Images Attached Images     

  10. #25
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    By the way I would have never believed how much magnetic pull these drivers have before they are demagnetized, but I am a believer now!!!
    Attached Images Attached Images    

  11. #26
    Maron Horonzakz
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    Wow I always wanted to see what that phase plug looked from both sides. Any luck in finding a TAD 4001 to take apart for compaireison.

  12. #27
    Maron Horonzakz
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    Why doe,s that top plate look like it has a double layer with a spacing. Whats that spacing for?

  13. #28
    Administrator Mr. Widget's Avatar
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    Quote Originally Posted by John
    Here are the parts that make up the 2440.
    Where is the throat?

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  14. #29
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    The Throats were history, that is why I got the pair for $20.00!!! They were cracked and are in many pieces now. Will have to get a pair.

  15. #30
    Senior Member Jakob's Avatar
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    Hi!

    How do You tell if a throat is broken?

    Regards: Jakob

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