SonoSub help Please

Discussion in 'Archived Threads 2001-2004' started by Lon_Coleman, Nov 13, 2001.

  1. Lon_Coleman

    Lon_Coleman Agent

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    Well, I thought I could figure it out. With all of the software programs out there and all of the tubes that others have built. I was wrong.
    I am trying to figure out how tall I should make my tube with lets say a 12' shiva and a 16' sonotube diameter. I will probably mount a AVA 250 on it.
    The programs completely throw me for a loop and I haven't found any one that has built a tube similar. P. Sun built one with 2 drivers but I don't know if that effects the size (height) of the tube.
    I am not am audiophile but I would like to build a clean sharp sounding sub for my home theater.
    Please help with any comments or suggestions
     
  2. Brian Bunge

    Brian Bunge Producer

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    Lon,
    The first thing we need to know is whether you're building a sealed or ported enclosure (and tuning frequency if ported) and what internal volume you plan on using. These should be the first thing you decide as far as your design goals. If you can give us this info. there will be more than enough folks here willing to help!
    Brian
     
  3. Lon_Coleman

    Lon_Coleman Agent

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    I was planning on a ported sub, and from my reading it sounds like I should have it tuned to the 20Hz area.
    As for internal volume... I have no idea. Lets put it this way. If someone can recommend what I should build then thats what I will do.
    Is sealed better?? Agian I am going for a clean bass sound.
    Thanks for the help so far
     
  4. Brian Bunge

    Brian Bunge Producer

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    Well, Adire has 3 different vented alignments for the Shiva, the smallest being the 85L enclosure tuned to 20Hz. Here's a link to their page with the different alignments for sealed, vented, and PR'd enclosures. If size is an issue, then the 85L vented enclosure might be the best for you.
    http://www.adireaudio.com/Tech%20Papers/shiva_apps.htm
    Brian
     
  5. Dustin B

    Dustin B Producer

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    Well the easiest then would be to just follow one of the designs off of the Adire's application notes for the Shiva. I like the EBS enclosure, so lets go with that. The EBS enclosure is 142.5L tuned to 18.1hz with their FP4 flared port kit (using the kits full 12" tube length).
    So a lets say you have a 13" long 4" wide tube. That tube will displace (pi x dia/2 squared x height of tube converted to L) 2.7L. The Shiva according to the white paper will displace about 3L. So now you know the gross volume your tube needs to displace. 142.5L + 2.7L + 3L = 148.2L.
    That was kind of anal, so lets just round it to 150L (in the end that won't make much of a difference and it will make it easier for you to describe what your sub is to others.
    So 16" diameter and 150L displacement needed means you need a sonotube that is
    150000 cubic cm/(pi x 413 square cm)= 116cm
    (8" squares is the same as 413 square cm)(150L is 150000 cubic cm)
    116cm is 45.75". So you'll need a tube that is 45.75" long. You'll need to add to that whatever length of each endcap you put inside the tube. Id if you do like I did (1" of each endcap inside the tube) you'll need it to be 47.75" long. some others have only put 3/4" inside the tube, in which case you'll need the tube to be 47.25" long.
    Now all these numbers assume your sonotube is actually 16" in diameter. My tube was called 18", but it was actually 18.75". To find the actual diameter of your sonotube, measure it's circumfrence and use that number to calculate the actual diameter, then plug the actual radius values into the math above to find a more accurate height.
    Oh and I do believe sonotube comes in 2" increments from like 4" all the way up to 60" or larger. So you should be able to get 14" sonotube which should work with a shiva (tube will just need to be taller).
    As a side note, I thought I'd explain why I'm taking the time to write this. After the long weekend for some reason I decided my class started at 10:30am, when in reality it starts at 11:30am, so as a result I walked into a class in session. Felt really stupid and walked out. So I now had an hour to kill. Knowing that, take my advice with a grain of salt [​IMG]
    [Edited last by Dustin B on November 13, 2001 at 10:59 AM]
    [Edited last by Dustin B on November 13, 2001 at 11:00 AM]
     

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