What is the formula for finding Cubic ft for a speaker box?

Discussion in 'Archived Threads 2001-2004' started by Sebastian, May 5, 2002.

  1. Sebastian

    Sebastian Second Unit

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    Is it HxWxD? or is that surface area?
     
  2. eric nyhof

    eric nyhof Stunt Coordinator

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    it is HxWxD, which would be in feet cubed.

    Surface area is feet squared and is only the are of a side
     
  3. Dustin B

    Dustin B Producer

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    Don't forget to account for the thickness of the walls, any bracing and any volume displaced by the driver and port if present.
     
  4. Wayne A. Pflughaupt

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    Of course, you have to use the interior H x W x D dimensions, or else subtract the wall thickness from the exterior measurement.

    If you are measuring in inches, divide the total cubic inches by 1728 to get the number in cubic ft.:

    E.g.:

    22” x 18” x 16” = 6336 cu. in.

    6336 ÷ 1728 = 3.6 cu. ft.

    As Dustin mentioned, you have to subtract the displacement of any braces from that figure (using the same method). Not sure how to figure the displacement of the driver – perhaps the manufacturer could tell you that.

    Regards,

    Wayne A. Pflughaupt
     
  5. Dustin B

    Dustin B Producer

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    You don't have to be that precise with the driver if you are reasonably precise with the rest. Use 5L for a 15" driver and 3L for a 12" driver. Should be close enough.
     
  6. Sebastian

    Sebastian Second Unit

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    Yeah that is what I thought. I think I may have had square feet confused with Cubit feet.

    Thanks guys
     

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