Magnetic Shielding Qustion

Discussion in 'Archived Threads 2001-2004' started by Greg_TSL, Oct 12, 2002.

  1. Greg_TSL

    Greg_TSL Stunt Coordinator

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    I'm constructing a cabinet for my large direct view HDTV and I am hoping to incorporate my 12" subwoofer into the structure.

    I will have more details forthcoming (as I figure out placement and costs) but I'm wondering if anyone has experience shielding a large speaker from a CRT or other electronics.

    I've been researching Mu Metals and Gauss meters a bit. This will probably wind up costing a lot if its even possible, but my only other option is to have a subwoofer in the middle of the home theater!
    TIA
    Greg
     
  2. www.stryke.com will sell subs with a bucking magnet attached to help shield the driver.
     
  3. Greg_TSL

    Greg_TSL Stunt Coordinator

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    Thanks for the link Anthony.
    To clarify, the cabinet is furniture, not a speaker enclosure, and my sub is a factory jobby, already constructed.
    If I cant properly shield the current sub, I may look into a DIY sub with active magnetic shielding.
    Given the price of the high quality shielding materials, it may be cost effective to go that route, but I seriously doubt my ability to build the sub (I failed shop).

    Since the cabinet has yet to be designed I can incorporate as much shielding as I can imagine...from steel to Mu Metal foil, to lots of wood, and hopefully at least a foot of space.
    I realize shielding magnetic energy isn't as simple as just placing something in between the source and what you hope to protect. I see some magnetic shields for CRT's like computer monitors in labs, and the sites discuss the need to almost fully enclose the monitor to get any sort of protection. I could enclose most of the subwoofer by placing shielding (either steel or Mu-foil) in the cabinet, leaving the front open, but the TV is simply too large to consider enclosing it.
    My fear is that I could spend a few grand building the thing and it wouldn't be effective. I can rent a Gauss meter for a few hundred bucks and measure what magnetic transmission is still present, but I'm not sure what level would be safe and what would cause damage over an extended period.
    As you can see I'm most likely way over my head, but I'm hoping to get any help, info, and support I can before heading into this project.
     
  4. Brian Bunge

    Brian Bunge Producer

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    Greg,

    Keep in mind that having your sub inside the cabinet can easily cause the cabinet to resonate. I had dual 12" subs installed in a very large cabinet and I could hear the vibrations from across the room. Unless you can effectively isolate the sub from the cabinet I'd skip that idea.

    Brian
     

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