Quick Help Needed w/Sub Positioning

Discussion in 'Speakers' started by Louisp, Mar 12, 2005.

  1. Louisp

    Louisp Stunt Coordinator

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    My Infinity sub is front firing with the port in the rear.

    The only wife approved location for my sub is behind the entertainment hardware which is a corner positioned at a 45 degree angle. To complicate matters one of the back walls is actually an arched opening into another room. Because of this opening the sub does not have a solid surface behind the port. Plus the woofer fires into the back of the hardware.

    My alternate plan is to mount 8" legs on the back of the sub so that it fires UP with the port opening pointing DOWN. The floor is carpet but if best I can place a hard surface under the sub and over the carpet.

    Please tell me if this is a workable alternative to normal placement.

    Thanks
     
  2. MikeNg

    MikeNg Second Unit

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    I don't think anyone can tell you for sure - you'll just have to try it out to see. Small changes in position/rotation make a difference so it may work for you.
    You could also try just rotating the sub 90 degrees so that it fires toward one of the side walls. LF is by and large non-directional so you don't need to 'aim' it at the listening position.

    Mike
     
  3. John Garcia

    John Garcia Executive Producer

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    Point the driver parallel to the longest wall for starters. I have a very similar setup. As Mike said, small changes can make noticable differences at your listening position. IMO, pointing it at the ceiling isn't going to buy you anything.
     
  4. Louisp

    Louisp Stunt Coordinator

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    The reason for pointing it at the ceiling was so the intake was over a solid surface AND so the woofer was firing along an unobstructed wall. Aiming the woofer along the side wall has it firing into hardware and a fireplace.

    I appreciate your comments.

    Lou
     
  5. David Judah

    David Judah Screenwriter

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    How much clearance do you have for the woofer? You really don't need that much. Also, not having the port firing into a solid surface is not a liability.

    If you don't have the option to move it to another location, then I guess it'll have to work. Maybe you'll get lucky.[​IMG]

    DJ
     
  6. Louisp

    Louisp Stunt Coordinator

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    The woofer has about a 2' clearence. What do you think?
     
  7. David Judah

    David Judah Screenwriter

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    It should be fine.
     
  8. Louisp

    Louisp Stunt Coordinator

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    Does it matter if the sub is elevated 18" off the floor?
     
  9. David Judah

    David Judah Screenwriter

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    I don't have any experience pulling the sub off the floor, but it always matters when you move the sub.
     
  10. John Garcia

    John Garcia Executive Producer

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    The port is an inlet/outlet, but not the way most think it is. It's there to relieve pressure from the driver's movement, not to allow bass to flow out of it. 2 feet is more than enough; even just 6 inches should be plenty.

    Raising it 18" off the floor may help, but the exact height that works best/well will be determined by your room.
     
  11. Greg Bright

    Greg Bright Second Unit

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    I do believe that there is a point where most of the sound comes from the port and not the woofer itself. Otherwise the driver would self-destruct from over-excursion.
     
  12. MikeNg

    MikeNg Second Unit

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    I believe that's the 'tuning point'.
     
  13. John Garcia

    John Garcia Executive Producer

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    At the tuning point, most of the acoustic energy is coming from the port, but an equivalent reduction in excursion occurs, so the result is sort of a wash. Over-excursion will ultimately result in bottoming out, not quite instant self destruction, though it's not a good thing over time.
     
  14. Louisp

    Louisp Stunt Coordinator

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    A hardy thanks for all the contribution's to this thread. After an evening of movie watching I can say that the sub has never sounded as good as it does now.
     

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