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thinking of new project using AL1804 driver

Discussion in 'Home Theater Projects' started by Chris Brock, Apr 14, 2004.

  1. JulianS

    JulianS Auditioning

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    im no expert on this, but wouldn't there be organ pipe/port resonance issues with such a long port? looking in unibox a 38 " long/deep port will resonate at about 160 hz
     
  2. Seth_L

    Seth_L Screenwriter

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    Yes, ports will resonate at certain frequencies. If they become too long that frequency can dip too low and cause problems.
     
  3. Chris Brock

    Chris Brock Second Unit

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    I might actually just end up going with an single 8" port. like the one in the XXX box above. that driver has a ton a displacement so if he has no problems with noise then i dont think i would. plus going with the slot port i would loose alot more internal airspace so the box would have to be larger.
     
  4. JulianS

    JulianS Auditioning

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    will a slot port with a bend in it have the same resonance problem?
     
  5. Seth_L

    Seth_L Screenwriter

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    Julian that is a good question. I've heard people say yes, and people say no.

    The people who say yes reference a tuba. It's all bent up but still plays low notes.

    The people who say no say that the a folded port is broken up and less prone to resonate.

    I tend to lean towards the yes, it will still resonate camp, but I really don't know a firm answer.
     
  6. JulianS

    JulianS Auditioning

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    Interesting, i think as long as you cross the sub over low enough the port resonance won't be a problem, the only thing is the resonance might support harmonic distortion, but even then I wonder if it will be noticable.
     
  7. James W. Johnson

    James W. Johnson Screenwriter

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    I just got a few of the AL1804s I am starting off with a 6 cuft net sealed box , i'll play with it awhile with my QSC 1850HD bridged for 1800 watts and my BFD then go from there.
     
  8. James W. Johnson

    James W. Johnson Screenwriter

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    I ended up using my 2 1804s in an IB, my wall is moving nearly 1/2" , see the video in this thread over at HTT.
    http://hometheatertalk.com/httalk/viewtopic.php?t=6686


    The 1804s are sweet, sweet ..snatch these up because they kick some serious tail! I can clip my QSC 1850HD and still I cannot get these drivers to bottom whatsoever! My meter don't read higher than 126dbs but I know I have been up in the 130s for a short time..this is the first time I have ever achieved these sort of SPLs.
     
  9. Chris Brock

    Chris Brock Second Unit

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    man!! this is really making me ancious to hear mine. i have my BFD and my XA-900 ready to go now. All i am waiting on is the 1804!! then it will be time to hit the table saw!!
     
  10. Chris Brock

    Chris Brock Second Unit

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    well when i finally get my driver I think I have decided on an enclosure. I think I am going to go with about 17.5ubes internal tuned to 15hz with a port that will be 3" x 28.5". Here is a quick drawing I did of what I have in mind. Any opinions would be greatly appriciated!!

    [​IMG]

    p.s. this drawing does not show the internal bracing. there will be alot of it!
     
  11. Kyle Richardson

    Kyle Richardson Screenwriter

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    Boy, thats a lot of room for that driver! I have mine in 10 cubes and its flat to about 18Hz.
     

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