Cone excursion - Xmax - and Lspcad

Discussion in 'Archived Threads 2001-2004' started by Fred Seger, Feb 23, 2001.

  1. Fred Seger

    Fred Seger Stunt Coordinator

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    This is kinda of a combo question.
    1) When you look at X-max specs are they always one-way?
    2) When you look at cone-excursion results in Lspcad are they referring to the one way Xmax or total movement which is always greater than 2x-Xmax( I think)
    Example
    I'm modeling a 6.5" driver that has a 3.15mm Xmax according the spec. Do I need to keep the cone excursion under 3.15mm or 6.3 mm?
    Thanks
     
  2. Greg Monfort

    Greg Monfort Supporting Actor

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    >1) When you look at X-max specs are they always one-way?
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    Correct.
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    >2) When you look at cone-excursion results in Lspcad are they referring to the one way Xmax or total movement which is always greater than 2x-Xmax( I think)
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    It shows peak-peak, with no consideration for Xmax, Xsus, or Xmech. It's up to you to know the various limits and multiply them 2x to see whether the driver's in trouble or not.
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    >I'm modeling a 6.5" driver that has a 3.15mm Xmax according the spec. Do I need to keep the cone excursion under 3.15mm or 6.3 mm?
    ====
    Yes, if Xmax is your personal limit, to keep distortion very low.
    GM
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    Loud is beautiful, if it's clean
     
  3. Fred Seger

    Fred Seger Stunt Coordinator

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    Thanks Greg for your reply.
    I used to use WinISD to model woofers/speakers. I don't think most people know that WinISD has no consideration for cone excursion when it plots the output. It's VERY important to consider this when designing a subwoofer or speaker. LspCAD is much better in that respect I think.
     
  4. Greg Monfort

    Greg Monfort Supporting Actor

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    >LspCAD is much better in that respect I think.
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    My pleasure! [​IMG]
    And evey other. WinISD is dangerous IMO due to this, and its errors.
    I use BoxPlot 3.0 for quick comparisons, as it shows Vd limitations, and I've yet to catch it in a serious error.
    GM
    ------------------
    Loud is beautiful, if it's clean
     

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