air flow resistant "aperiodic" damping device

Discussion in 'Archived Threads 2001-2004' started by Ryan T, Oct 7, 2001.

  1. Ryan T

    Ryan T Second Unit

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    Hi, when I was looking through the ports sections at Parts Express I saw this, its a SCAN SPEAK 29001 FLOW RESISTANCE VENT. I'm wondering what this does for a sealed box and how/why this is supposed to work, also I’m wondering if this would be good for a 3.0 Cubic ft. sealed shiva?
    Ryan
    P.S. here is the link http://www.partsexpress.com/pe/showd...=7832&CATID=48
     
  2. Jeffrey Noel

    Jeffrey Noel Screenwriter

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    Ryan,
    I am going to be making a 3ft^3 enclosure (from partsexpress.com) and combining a Shiva with it also. I too noticed these vents and was wondering if anyone has heard anything about these. But for you, I would suggest using a 15" passive radiator from Adire. As Jack suggested, I e-mailed Dan, Mr. Adire, personnally, and he also suggested using a PR. He also suggested stuffing the 3ft^3 box with 48 ounces of polyfill and adding 320 grams to the passive radiator. He said that it should pretty decent performance.
    Are you planning on making your box from scratch, or were you also looking at the 3ft^3 pre-cut box from partsexpress?
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    God bless :usa:
    jeffrey noel
    My DVD Collection
     
  3. Ryan T

    Ryan T Second Unit

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    Jeffrey I'm going to try and use a box I have for a car sub that’s 3 cubic ft. and if that does not work I’m going to build one with my grandpa. I would like to do a passive radiator but I don’t know if that will be an option considering the cost and how much money I have right now (I’m really trying to stay around $150 but could go higher if it would really help performance). I get paid 30 buck a week, would it be worth it to wait an extra 3 weeks and buy a passive radiator with my shiva. The only other problem is that the box I have right now is 14"W 14"D 30"L so there would be no room for a passive radiator. I would have to buy a box from parts express or wait until I can get to my grandpas house, the reason I have to wait until I get to my grandpas house is because he has a bunch of woodworking tools that I would need to use to make a halfway decent speaker box. That pre cut box from parts express look really nice wish it wasn’t so expensive [​IMG].
    Ryan
     
  4. Bob Ahlberg

    Bob Ahlberg Agent

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    Ryan...
    If you use the sub box you already have, be sure it is braced properly. Most prefab sub boxes and even those made at car audio shops are often not braced at all. If you want max performance out of your Shiva, it needs a solid box.
    Secondly, the aperiodic vents accomplish (at least) two things. First, they cause the driver to "see" a slightly larger enclosure because they bleed off just a bit of the internal pressure in the box. Secondly, they smooth the rolloff and the impedance of the driver at F3.
    Hope that helps,
    Bob
     
  5. Ryan T

    Ryan T Second Unit

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    Thanks for all the replies I guess my only other questions would it be wise to put three of this things in my 3 Cu. Ft. sub box or not. Like I said before I’m going to use a shiva, do you think it would improve performance much or not?
    Ryan
     
  6. Jeffrey Noel

    Jeffrey Noel Screenwriter

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    Ryan,
    I would go ahead and use three, just because partsexpress recommends using 3 if your box is larger than 2.75ft^3.
    If you do go with these, please report back and tell us how they work. I haven't heard any reviews of using them, so I'd really like to see if they help. Heck, you could be starting a new "fad". [​IMG]
    Good luck with whatever you choose to do. Can't go wrong with a SHIVA!!
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    God bless :usa:
    jeffrey noel
    My DVD Collection
     

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