Blue print 1803 loss of db in sealed vs. ported

Discussion in 'Archived Threads 2001-2004' started by Greg P, Sep 27, 2001.

  1. Greg P

    Greg P Stunt Coordinator

    Jan 7, 2001
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    From my new and limited knowledge of sub building, I have learned that ported subs have a 3db efficiency over sealed, and after the sealed has hit its F3 the ported will have about 6db more output. Is this correct?
    My sub project was going to be an isobaric Tempest, but for one thing that is very complicated for a first time project and that new 1803 looks unbelievable.
    I was thinking that it would be not to advnantagous to put the 1803 in a ported design, as for one the driver can below so low I dont need output or tuning to 13hz because I dont listen frequencies that low. So I think Im really only giving up 3db by going sealed.
    Can you guys give me a link or explain to me about the Linkwitz chip?
    Its made for a sealed box, right? The only understanding I have of it as it kind of works like an ELF system but more efficient.
    I thought from your guys discussion that this driver would only need a box around the size of a Tempest to get the same Q?
    Sorry about all the questions, I know its a mouthful, but I just want to learn more.
  2. Jack Gilvey

    Jack Gilvey Producer

    Mar 13, 1999
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    Here are some links on the Linkwitz transform circuit:
    This would be the best way to use this driver sealed. Vented can potentially give much more output, but needs a larger box. 14ft^3 tuned to 18Hz looks ideal for a ported design.
    The best way to see what different loadings and alignments do is to model them yourself. This is an excellent program to do just that:
    [Edited last by Jack Gilvey on September 30, 2001 at 11:51 AM]

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