Room modes are the DEVIL!

Discussion in 'Archived Threads 2001-2004' started by Trenton McNeil, Feb 21, 2001.

  1. Trenton McNeil

    Trenton McNeil Second Unit

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    Sonosub in the corner, guess where the HUGE dead spot is? Yep....about a 5 foot radius right around the prime seating location....
    Anyone know how to place a sub so that this isn't a problem!?
    Don't get me wrong, its still loud and nice and all, but I'd rather not have to rattle the dishes in the kitchen just to get decent bass output at my seating location...
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    I wish I had a dollar for every time I spent a dollar, because then, yahoo!,
    I'd have all my money back. -- Deep Thoughts, by Jack Handey
     
  2. John E Janowitz

    John E Janowitz Second Unit

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    The one trick usually used is to actually hook up the sub in the listening position. Then go around the room and find where the bass is the flattest, loudest, etc, what ever you happen to be going for. Then put the sub in that spot. The room modes should work directly in reverse and your output should be what you are looking for in the seating position. The only problem I've seen is a few times that I did this, the best position for the sub was not somewhere I could actually put it, so I had to compromise.
    Also you may want to look into elevating the subwoofer. I've solved dead spots a few times by corner loading the subwoofer up at the ceiling instead of down at the floor. Furniture, open doorway's, things like that effect the room modes on the ground, but on the ceiling these are not as much of an issue.
    John
     
  3. Trenton McNeil

    Trenton McNeil Second Unit

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    The only problem is...the sub is about 5 feet tall. [​IMG]
    I'm going to go take some pictures now for you guys....
    new thread in a few!
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    I wish I had a dollar for every time I spent a dollar, because then, yahoo!,
    I'd have all my money back. -- Deep Thoughts, by Jack Handey
     
  4. Philip Hamm

    Philip Hamm Lead Actor

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    Trenton,
    I've got a similar problem in my room, with the dead spot right at the primary seating location. I don't have much in the way of options as to where to locate the sub unfortunately. And my dead spot is not very severe, only a couple dB.
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    Philip Hamm
    AIM: PhilBiker
     
  5. Greg Monfort

    Greg Monfort Supporting Actor

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    Yep. Moving the sub along a wall won't help much since the null is a function of the room's length. Large panel diffusers will help, but have to be out in the room, so no help there. Using John's suggested technique will average the FR a bunch though, as there's peaks to go with the nulls.
    WRT ceiling loaded, turn the sub upside down to see how much, if any it helps. You may need to re-think your design a bit if you can't find a more suitable location for either the sub/listening position.
    GM
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  6. Ron-P

    Ron-P Producer

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  7. FrankD

    FrankD Stunt Coordinator

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    Basically try to get the sub in its best position. Do what some of the other posts suggest above or just move it around in the available locations and settle for the best. With the problems you described it sometimes means taking it out of the corners and maybe away from the walls as much as possible. You can then use a parametric eq like the Berhinger Feedback Destroyer 1100pro to reduce the humps and then increase the overall sub volume to get the desired level (after reducing humps, overall sub volume may decrease). By reducing the humps you are trying to bring down the higher levels to what the lowest level is reading.
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