Duel Shiva Transmission line

Discussion in 'Home Theater Projects' started by Stuart Mundy, Apr 19, 2004.

  1. Stuart Mundy

    Stuart Mundy Agent

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    Hi all looking for some advice on building a duel shiva transmission line sub, I'm currently running a Shiva 142ltr EBS as well as a 88ltr sealed Shiva, and I am looking for a new project.
    I've come across a couple of sites regarding TL's and they have really got my interest up, I am now probably 30% movies and 70% music, I have some 10" PVC pipe in 6' lenghts and am itching to do something with them.
    I was thinking about building a 14" box to mount the tube to similar to this http://www.t-linespeakers.org/projects/steve/index.html can someone advise whether the smaller length & diamter tube would be any good and also should the tube be stuffed like a sealed sub or lined ?
    Cheers
    Stuart
     
  2. Greg Monfort

    Greg Monfort Supporting Actor

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    As pipe CSA decreases, pipe length decreases and LF output rolls off. Using MJK's worksheet, a 10" pipe ~130" long will tune it down to Fs with a ~6dB/octave roll off beginning around 60Hz, which is pretty much the HF XO point due to a wide/deep notch from ~70-102Hz. Doing a ~140" line 14" square is ~6dB more efficient and goes a bit lower.

    Download the Mathcad demo if you don't have a licensed version 8 or newer and MJK's worksheet to sim it at http://www.quarter-wave.com/

    GM
     
  3. TimForman

    TimForman Supporting Actor

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    If you can do a full length line as Greg is suggesting stuffing will be minimal. I used a large amount of stuffing so I could shorten the line length and simulate a longer one. Using MJK's worksheet will get you going in the right direction but in the end you'll want to experiment with different amounts of stuffing.
     

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