You have been "Out-Woofed" Woofer Challenge

Discussion in 'Archived Threads 2001-2004' started by John A. Casler, May 7, 2002.

  1. John A. Casler

    John A. Casler Second Unit

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    I just hooked up a newly arrived Earthquake sub yesterday and realized that I have an enormous amount of "piston" area in my system.

    Can anyone "outwoof" (radiate) me?

    Front L&R Legacy Sig III (10"/10"/10")x 2

    Front Sub - VMPS LARGER (12"/15"/15")

    Rear L&R - VMPS TowerII (12"/12"/12") x 2

    Rear sub - Earthquake SuperNova 15 (15"/15")

    That is 6 x 10", 7 x 12", 4 x 15" woofers or passive radiators.

    I almost forgot, I also have a HSU VTF2 but haven't added it in yet (actually the Earthquake replaced it)

    OK, I've thrown down the gauntlet. Somebody has to have more than this.

    John Casler
     
  2. Saurav

    Saurav Cinematographer

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    Decibels, inches, and number of surround channels. The phallic symbols of the new millenium [​IMG]
     
  3. Dustin B

    Dustin B Producer

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    Thomas W's 12 Shiva's Dancing IB should out displace you. Twelve Adire Shiva drivers in a infinite baffel manifold. Total Vd is something like 18.6L and that doesn't include any of his other speakers.

    Also one of those 15" in the larger sub doesn't count because it's a passive radiator, same with one 15" from the Earthquake. I'm not sure if there are any more passive radiators in your towers or not though.
     
  4. John A. Casler

    John A. Casler Second Unit

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  5. farnamT

    farnamT Agent

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    Thats alot of woofers. But how much air they move is important. The earthquake will move probably the same air all your woofers on your speakers move together. An passive radiators do count. At sub frequences they move about the same as the woofer.
     
  6. Mike Strassburg

    Mike Strassburg Second Unit

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    I'll give it a shot. Here's my current Klipsch Legend/sonosub 7.1 system:
    Mains: 4 x 12" - KLF-30's
    CC: 2 x 10" - KLF-10 converted to CC
    Surrounds: 4 x 10" - KLF-20's
    Back centers: 4 x 10" - KLF-10's
    Sub: 2 x 15" - dual Tempests
    Total
    4 x 12"
    10 x 10"
    2 x 15"
    Of course I'm already thinking about another dual Tempest sub. When I crank up the old 3802 to around +4 that's a LOT of "woofage" for a 15' x 22' room!
    P.S. Win or lose I've probably got the "horniest" system out there...
    P.S.S. "Phallic symbol"...NO. "Sexual Aid"...MAYBE. Cranking all those woofers makes more than my RS meter point North [​IMG]
     
  7. Ryan Schnacke

    Ryan Schnacke Supporting Actor

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    If passive radiators count then ports have to count since they essentially do the same thing. But I think Dustin had the right idea - only count active drivers.
     
  8. Jeff_M

    Jeff_M Stunt Coordinator

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    Could someone quickly explain to me how a passive radiator operates? How does it equate to a port?
     
  9. Ryan Schnacke

    Ryan Schnacke Supporting Actor

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    A passive radiator is energized by the active driver. As the active driver radiates near the the tuning frequency of the particular alignment the passive radiator travel increases and the active driver travel actually decreases a bit to a local minimum. At the tuning frequency a significant portion of the sound pressure comes from the PR.

    Similarly, air movement in a port is energized by the active driver. As the active driver radiates near the tuning frequency of the particular alignment the air speed increases and the active driver travel decreases a bit to a local minimum. At the tuning frequency a significant portion of the sound pressure comes from the port.

    In the same alignment they will perform very similarly. So it is incorrect to say that woofer X with a passive radiator will outperform woofer X with "only" a port.
     
  10. Ned

    Ned Supporting Actor

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    Driver *size* is only half the story, the other is *stroke*, cough, xmax that is.
     
  11. Dustin B

    Dustin B Producer

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    As the passive radiator starts to move more air, the driver moves less, until you get below tuning, but things go all out of whack pretty quickly below tuning.
    It's impossible to quickly explain what a port of PR do, but they definately do the exact same thing.
    Here are a couple links that will allow you to answer your own question:
    http://www.hometheaterhifi.com/volum...ayporting.html
    Doh, the Lambda FAQ is no longer up, grr, that link did an excellent job of explaining PRs. Essentially a PR acts the same as a port with the same surface area as the Sp (effective surface area) of the PR. You then figure out how long that port would need to be to tune to a particular frequency, then making the PR weigh as much as the air that would be contained in that port will result in the same tuning. Problem is the Vp (how much air the PR can displace with its motion) needs to be at least twice that of the active driver (preferably 3-4 times). Advantage of the PR is you can have the equivalent of a much larger port in a smaller box. Problem is the moving mass of the PR can get pretty large, so if you don't have two opposing each other the box can wabble pretty bad. There are a few other problems that are over my head as well.
     
  12. Tom Brennan

    Tom Brennan Screenwriter

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    Ned---True enough as far as it goes but I think that large diaphragm area short-stroking sounds much better than small area long-stroking. Sounds alot cleaner and "jumpier" to me. My opinion. In any case I have 6-15s operating below 100hz; the Altec 515Bs in my Altec A5s and a pair of JBL Pro 4648s augmenting the A5s below 100hz, each 4648 has two 15" 2226s. IME only such an array of large, efficient, short-stroking drivers can match the dynamics and clarity of the rig's horn-loading above 100hz.
     
  13. EricK

    EricK Second Unit

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    Ok lemme see....don't know if I add up...
    Klipsch KLF 20's x6 dual 10" woofers (fronts, sides, surrounds)
    Klipsch KLF-C7 x1 single 8" woofer (center)
    Earthquake 15" sub (a15/p15)
    Velodyne 12" sub (a12/p10)
    M & K 12" sub (a12)
    Mike:
    I'm pretty "horny" myself...[​IMG]
     
  14. Andrew Pratt

    Andrew Pratt Producer

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    hmm so what about 7 large magnepan speakers in one room plus a dual tempest IB sub[​IMG]
     
  15. Saurav

    Saurav Cinematographer

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    There you go, planars - now you can multiply height by width and count square inches [​IMG]
     
  16. Chris PC

    Chris PC Producer

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    Geez, I guess I don't quite cut it, but not too shabby non-the-less compared to my old setup of two 8 inch woofers:
    Current setup:
    10 x 6.5" woofers in ported enclosures plus 2 x 12" woofers in sealed encosure as follows
    3 x 6.5" woofers x 2 for each PSB Image 6T
    2 x 6.5" woofers for Image 9C center
    2 x 6.5" woofer for surround 2 B's (1 woofer each 2B)
    2 x 12" woofers in sealed enclosure of single Mirage Sub [​IMG]
    Front end looks scary with grilles off. Eight! woofers staring at you [​IMG]
    Small room, more than enough bass for me [​IMG]
     
  17. Greg_R

    Greg_R Screenwriter

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    Dual Stryke HE15s + 4 18" PRs (slight modification from their kit design). I also have a Paradigm Servo-15 sitting in the corner but never use it...
    I think Tom V will win the prize (there's a pic floating around of ~15 sonotube subs in his living room)...
     
  18. Mike Strassburg

    Mike Strassburg Second Unit

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  19. Juan Castillo

    Juan Castillo Second Unit

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    Find that pic Greg!
     
  20. John A. Casler

    John A. Casler Second Unit

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    "I think Tom V will win the prize (there's a pic floating around of ~15 sonotube subs in his living room)..."
    It must look like a scene from "Aliens"!
    At least they "hit" you in the chest rather than coming out of it. [​IMG]
     

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