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Thread: DIY-project: JBL Kebnekaise S4365

  1. #76
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    Quote Originally Posted by pos View Post
    I used that calculator, and it gave me accurate results:
    http://www.psp-inc.com/tools2.html

    It is meant for the flared precision ports sold on parts express, but works just as well for the JET70 ones that can be found in europe
    Nice!
    This one gave me a little bit longer port-lenght than Flodstroem suggested.
    6.9" lenght for 28Hz tuning.
    8.9" length for 25Hz tuning.

    (Volume of box:5 cu ft, Port-diameter 2.7)

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  3. #78
    Senior Member Flodstroem's Avatar
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    Quote Originally Posted by bubbleboy76 View Post
    Nice!
    This one gave me a little bit longer port-lenght than Flodstroem suggested.
    6.9" lenght for 28Hz tuning.
    8.9" length for 25Hz tuning.

    (Volume of box:5 cu ft, Port-diameter 2.7)
    Yea, that could be the case but you have calculated only by volume but my sims are based on a real cabinet with exact your specified
    internal dimension including damping mtrl woofer and port location. Might be some differences due to that. But no matter how you do the
    calculations, this is only a hint of what length you should start with. Real tuning will be done after checking a finished build and that will be very
    exciting
    Flodstroem

  4. #79
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    The way of testing actual tuning frequency without measuring impedance, I read it somewhere here but forgot it.
    Playing test-tones and feel with the fingers when the port is "excited"?

  5. #80
    Senior Member srm51555's Avatar
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    Quote Originally Posted by bubbleboy76 View Post
    The way of testing actual tuning frequency without measuring impedance, I read it somewhere here but forgot it.
    Playing test-tones and feel with the fingers when the port is "excited"?
    Here and the post after are good ways to test.

  6. #81
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    Thanks! Saving it here for me to remember.

    Quote Originally Posted by pos View Post
    Another (less precise, +/- 1Hz) method is to use a signal generator (I use a simple iphone app called "signal gen" for this) while touching the cone and find the frequency for which the cone movement is at a minimum (and air movement from the ports maximal).

    With this method I found my current M2 build was tuned to around 24 or 25Hz (the tubes are too long, I prefer to aim for a lower tuning frequency and then cut them step by step...).

  7. #82
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    Some minor details updated.
    Attached Images Attached Images  

  8. #83
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    Small additions again.
    I got the BR-ports, and they did not have the same dimensions as stated on the website where I bought them. But the important one was correct, the internal tube diameter.
    I will be able to pull out the BR-port without removing the woofer, that is a good thing. The inner flared end is smaller than the mounting hole will be.

    I also got the sheep wool damping. This is an ecological project!
    But it is thicker than I thought. 40mm. Is this good or bad? M2 has like 20mm damping thickness, I think. 4365, I do not know. Maybe I should not cover all the internal walls?
    Attached Images Attached Images  

  9. #84
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    Where can the speaker grill connectors used in JBL 4365 be bought?

    I found this at home, I think it is from the 4365s.

    Outer diameter 12mm
    inner hole diameter 5mm
    depth 20mm
    Attached Images Attached Images  

  10. #85
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    4365 Exploded view.
    Attached Images Attached Images  

  11. #86
    Senior Member Flodstroem's Avatar
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    If you are not locked on those JBLś, HiFi-Kit has some that I have used for years. But they are not "rock strong" tough
    http://www.hifikit.se/tillbehor/gall...ntfastsattning
    Flodstroem

  12. #87
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    The "problem" is that I will use the original 4365 speaker grille.

  13. #88
    Senior Member pos's Avatar
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    If the pins are similar to the one on S4700/M2 grills then you can try part 333249-001 (L820 grill cup black)
    Got them from speaker exchange for a whopping $2.80 each.

  14. #89
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    Quote Originally Posted by pos View Post
    If the pins are similar to the one on S4700/M2 grills then you can try part 333249-001 (L820 grill cup black)
    Got them from speaker exchange for a whopping $2.80 each.
    Nice. That is the same partnumber as item 8 on the 4365 exploded view. I could not find it on their website, and I did not want to ask them because they are a bit tired of me.

  15. #90
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    I still have not got a quote from my carpenter on the rounded shape box. I think he do not want to start anything before I have all the components.

    I have a plan B, if the round shape gets too expensive to build. Something like this:
    http://errnum.com/html/coax_speaker_build.html

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