Vented AV15 enclosure?

Discussion in 'Archived Threads 2001-2004' started by David Lorenzo, Feb 26, 2003.

  1. David Lorenzo

    David Lorenzo Stunt Coordinator

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    Hi guys,

    I am trying to design a ported enclosure for a Stryke AV15. Here is what I have planned as of now. Please offer any corrections or advice.

    All walls will be 1.5" thick MDF. No internal bracing. Will the thick walls offer enough support so that I won't need any bracing?

    The inner dimensions will be 23x23x23 inches. Outer will be a 26" cube.

    I plan on having two 3" flared ports tuned to 16-17 Hz. Do I have to add any length to the ports since they are flared? Is .11 mach speed good?

    Does WinISD take into account the volume of the ports being used? For instance if I say the box is 180L does WinISD assume the volume does not include the port volume? Or do I have to account for that myself?

    Thanks
    David
     
  2. KyleGS

    KyleGS Second Unit

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    I'll try to tackle a few of the questions. I asked a similar question about bracing awhile back and the concensus was that a moderately braced .75" walled enclosure would be structurally more sound and dead than a 1.5" bare enclosure. I think with that size box I would at least run a single horizontal brace with some "L" triangles attached to the middle of the long panel runs. If you were dead set on no bracing I would use baltic birch sheets or a sandwich of mdf and BB.

    When I modeled it up you can't fit a pair of 4in pipes. So I guess your design will have to do unless you go with a passive radiator design. You may hear a little chuffing with two 3in ports- that AV15 can move some air.

    WinISD or WINISDpro DO NOT take port volume into account. Its looking at net volume. HERE'S a link that will estimate the volume taken up by the driver and ports but you will need to know the driver displacement in cf. THEN you should add the brace displacement if you decide to use it. G'luck

    HERE'S

    Scroll down about a-third the way.
     
  3. KyleGS

    KyleGS Second Unit

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    Sorry- on that link look at the right menu and go down to BASIC ENC. CALCS click that and then go down about 1/3 the way.
     
  4. David Lorenzo

    David Lorenzo Stunt Coordinator

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    Hi KyleGS

    Thanks for the advice. It is very much appreciated. This is my first time trying to design an enclosure so getting a second opinion is very valuable to me right now. I want to get it right the first time.

    I am not set on having no bracing at all. I just thought I wouldn't if it wasn't necessary, but I will now since you recommend it. How much volume do you think the bracing will take up? Just a ball park figure will be helpful.

    Edit: I could just use three 3 inch ports right? Then I would have more than enough vent area I think.
     
  5. Dan Hine

    Dan Hine Screenwriter

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  6. David Lorenzo

    David Lorenzo Stunt Coordinator

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    Yes they are [​IMG]. WinISD is awesome. I just downloaded it a few hours ago. I can't find my Excel CD so I can't use UniBox.

    I should have clarified a bit more. I was just asking if there were anything inherently wrong with using 3 ports. My plan now is a box with 25" internal walls. I could use three 3" ports tuned to 17Hz. I'm not 100% sure yet about the final dimensions until I find out exactly how much volume a plate amp and an AV15 would take up. Any one know, particularly about the AV15?
     
  7. Jack Gilvey

    Jack Gilvey Producer

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    I wouldn't bother with 3 3" ports with the AV15 unless you were only going to be using it at only a fraction of its capabilities. I like it in ~200 liters with a 6" port tuned to 18Hz.
     
  8. Craig Woodhall

    Craig Woodhall Supporting Actor

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  9. KyleGS

    KyleGS Second Unit

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    Just for a ballpark- I use bracing similar to Adire Audio and a double baffle- my 100L box came out with 5.5L of bracing or 0.2cf. Here's a link to the pdf. The displacement on my 15" Tempest is 5 L or .178cf. I was told that the plate amp does not displace enough to figure in on calculations. Therefore I added 10.5L of displacement to my 100L design- totaling 110.5L gross internal volume. Your AV15 probably displaces 6-7L as it has a larger motor structure. Keep in mind that if you are off by a liter or two no real difference will be heard. Definately download WinISD PRO. Its addictive- I've spent days designing subs with that program.

    Try this for some bracing ideas.
    Tempest Design with bracing


    Here's a link to a sub I built that is 122L sealed. I used "moderate" horizontal bracing AND ended up with 1.5" walls. (3/4" mdf and 3/4" softwood)
    PAGE 1

    PAGE 2
     

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