Flared port question(s)

Discussion in 'Home Theater Projects' started by Craig Woodhall, Jun 22, 2003.

  1. Craig Woodhall

    Craig Woodhall Supporting Actor

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    Hey guys, i am building a ported shiva for my car. I was shooting for one of the adire alignments of 2ft^3, 25hz with a 3" flared port.

    After building my box, subtracting braces and driver, I ended up at 2.23ft^3. What size port do I need to maintain the 25hz tuning? Also, do i use the flare on just one side or both? Winisd says 11.42 inches but I don't know if it accounts for the volume the port takes up and the flare(s) on the ends?

    .. sorry for the long post. :b

    Craig
     
  2. Phil~E~Guy

    Phil~E~Guy Extra

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    Subtract the port volume if it is within the enclosure.

    It extending the port outside the enclosure, do not subtract the port volume for areas extending from encloser.
     
  3. Phil~E~Guy

    Phil~E~Guy Extra

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    Also, partsexpress.com has a Dayton DVC 12" #295-185 for $109. It is nearly match for the Adire Shiva.
     
  4. Patrick Sun

    Patrick Sun Moderator
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    Yes, once you figure out roughly how much volume the 11.4" long port takes up (treat it like a solid piece inside the box), subtract that from the total net box volume for the new net box volume. And then plug that value into the WinISD (or whatever program you're using), to get the length needed to tune the box to 25Hz. If it's near 10"-11", just leave things as is. If it needs to be cut down a little bit, then do so, but don't get too anal about finding the impact of a little extra volume with a slightly shorter port.

    Also, whatever length you need, add 1 inch to the end-to-end length of the flared port (with both flared ends installed). If you need 11", then cut the center tube to the length that makes the total end-to-end length of the flared port 12".
     
  5. Craig Woodhall

    Craig Woodhall Supporting Actor

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    thanks guys, that makes sense.. i almost got the port thing down, its the flared thing that confused me..

    Craig
     
  6. Brian Bunge

    Brian Bunge Producer

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    Craig,

    Sorry I didn't respond to your email earlier. I've been at a customer's house for a few hours and just got back. Let me know if you still need some clarification.
     
  7. Sorry I didn't respond fo your email earlier. I've been in the lab for a few hours and just got back to the office. Let me know if you still need some clarification.

    [​IMG]
     
  8. Craig Woodhall

    Craig Woodhall Supporting Actor

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    hehe, my DIY expert friends! I can always count on Pat, Brian, Tony, DustinB and Jack.. thanks again, guys.
     
  9. Craig Woodhall

    Craig Woodhall Supporting Actor

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    oops. double post..
     

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