Infinite Baffle Subs: What works? What doesn't? Is it GOOD?

Discussion in 'Archived Threads 2001-2004' started by Javier_Huerta, Dec 17, 2002.

  1. Javier_Huerta

    Javier_Huerta Supporting Actor

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    Hi all!
    This place is as intoxicating as anything! I like it a lot. Keeps me learning, and learning.
    So anyway, I've been reading a bit about Infinite Baffles. I've visited the Cult (?) of the Infinite Baffle web page. I'm baffled by all the info I've found. [​IMG]
    Still, any firsthand experience with this baffling subject will be much appreciated.
    First of all, would this driver suffice?
    FS: 20 Hz
    Qts: 0.641
    Qes: 0.607
    Qms: 11.470
    Xmax: +-17 mm
    Dia: 15"
    DVC's. 4 ohms each
    I'd be powering 4 of these drivers with a PE 250W plate amp.
    Assuming a rectangular room (18 x 12 x 9 ft), do you think an IB would be a good choice? What kind of sound would I be looking at? Would I have enough headroom and punch for HT?
    So many questions... so little money. [​IMG]
    TIA!
     
  2. RayJK

    RayJK Stunt Coordinator

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    Do you have the rest of the specs? VAS, RE, LE? Brand and model could be helpful too.
     
  3. Jack Gilvey

    Jack Gilvey Producer

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    The FAQ, gallery, and forum page of the cult is all first-hand experience. It's a large sealed box.
     
  4. Javier_Huerta

    Javier_Huerta Supporting Actor

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  5. RayJK

    RayJK Stunt Coordinator

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    These seem to work fairly well but it is hard to model an IB setup. Running 4 of them in series/parallel with Unibox in a simulated 10,000L volume they came out pretty well with an Fb of 12.35 hz and an F3 of 11.07 hz but you can only run 75 watts per driver and are excursion limited to 12hz. This sould only give you an idea becuase IB doesn't model exactly as a GIANT sealed box. Do you have the SD spec?
     
  6. ThomasW

    ThomasW Cinematographer

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    IB's provide the finest quality bass available. Using an IB one will be able to hear details in the music that lesser subs just turn into a blurr.

    BUT if you're a fan of REALLY REALLY LOUD BASS; then multiple drivers are mandatory, so start with a pile of 15"s

    When modeling an IB remember that the 'box' size should be 4-10X the total Vas of all the drivers being used.
     
  7. Javier_Huerta

    Javier_Huerta Supporting Actor

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    Ray, thanks for the input. I couldn't find the SD spec anywhere, so I used 780 cm2 as a starting point. Given those figures, I thought I could run 80 watts to each driver without blowing the thing up.
    Thomas, I'm a fan of big bass, so that's the reason I suppose 4 of those drivers would suffice. Am I right? Would I need more drivers for HT-reference level bass?
    There's a method to this madness, actually. An Internet store ripped me off big time (it's in México, so I guess nobody would benefit if I named it - ok, it's www.decompras.com), and they sold me stuff they hadn't in existance. If I don't buy anything from them, the bank has warned me, I might lose my money. So I found the drivers I mentioned above for around $80 each. If I buy 4 of them, I am even with the store.
    After looking at the specs and modeling them for a long time, I thought maybe an IB driver would be a good idea. I do have an unused space in the room, and the subs look cool enough to be displayed in one of my walls (the rear wall, actually - I'll get the PE plate amp, so I'll have adjustable phase).
    Any thoughts about it?
     
  8. RayJK

    RayJK Stunt Coordinator

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    Please ignore the numbers I posted before, I was looking at the vented graphs and not the closed box ones. For a leaky (Ql=5) sealed box of 10,000L the Xmax is reached at 19.8hz with 75 watt per speaker input. This is a volume level of 115db without any room gain. Different programs are giving varied readings but as long as you aren't looking for rock concert volumes at 16hz these will work.

    $80 US apiece is a pretty good price from what I saw during a quick look. Norm seems to be $95-105 with the lowest I found at $75. Shipping is what hurts here and can be even worse for you I would imagine. $60-70 to ship 4 18 lb subs seems to be a bit high IMO.
     
  9. ThomasW

    ThomasW Cinematographer

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    Javier
     
  10. Jack Gilvey

    Jack Gilvey Producer

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    One of the most common misconceptions about IB loading is that a driver will somehow have less output in an IB since it will take less power to get to Xmax at a given frequency.
    Max SPL at a given low bass frequency will be determined by a driver's Vd, not input power (unless the box is really small).
     

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