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custom designing a sub

Discussion in 'Home Cinema Building DIY' started by james.miller, Apr 18, 2003.

  1. james.miller

    james.miller
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    i have seen a lot of people here says things like "this driver is flat to x frequency in a vented box of y liters"

    im curious, do any of you worry about phase responce? the general feeling i got is that you are making boxes as big as you can to get the responce as flat as you can. That all very well, but thats a bad way of doing it.

    I made that same mistake with my 12inch lightning audio (rockford Fosgate) strike DVC sub. its in a 3.5 cubic foot box and is flat right down to around 17hz. Flat, but the phase responce is horrid. at around 90hz the phase totally shifts 180degrees meaning its effectivly useless above that point. Making boxes bigger makes the problem worse.

    i was just wondering if anyone took this into account? (oh and im not flaming anybody lol)
     
  2. james.miller

    james.miller
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    bump. anybody?
     
  3. ReTrO

    ReTrO
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    I try to stick near reference designs and mod the enclosures to shape more than anything else.

    The tools in WinIsd are good to check all these bits.
     
  4. micb3rd

    micb3rd
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    Your subwoofer is it Lighning Audio or Rockford fosegate?

    Strike is another subwoofer company which make some good DIY drivers.


    LA and RF are two distictly different subwoofer producers for Car Audio, almost all Lightning Audio and Rockford fosegate subwoofer drivers are not really suted to home application they do not model very well in home, there FS are often way to high and x-max limits are farly low compaired to more common DIY subwoofer drivers.


    Thare are quite a few subwoofer drivers that work extremely well in very large ported enclosures, a 214 liter AdireAudio Tempest comes to mind, very popular in the US and Canada.

    Personally I would never want a subwoofer to play above 80 hz let alone 90 hz, subwoofer/room localisation of bass would be high at this point.
     
  5. james.miller

    james.miller
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    lightning audio is a part of the Rockford corporation, as is mb quartz.

    the sub i have is a lightning audio 12" strike Dual voice coil s12.2.4. rated as follow:
    fs : 25hz
    xmax : 6.8mm.
    400w rms, 800peak

    for the money i payed, its very good indeed.

    i too dont use anything above 80, infact mine rolls off slightly before that which is just as well. My point was that people generally dont seem to be taking phase responce into account, or at least, they dont appear to be.
     

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