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Shielding a sub?

Discussion in 'Archived Threads 2001-2004' started by ChrisAttebery, Jun 18, 2002.

  1. ChrisAttebery

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    Hi Guys,

    I want to build a sub that will be set under my entertainment center. It will not be in physical contact with the unit, but I am worried that the sub will electromagneticly interfere with my receiver, DVD, VCR, TV etc. Is there an easy way to shield the sub?

    Thanks for your help,


    Chris Attebery
     
  2. AndersP

    AndersP Stunt Coordinator

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    The bigger the magnet, the bigger the problem It seems. Serious subs use drivers with big magnets. It can be done, but like we say in the medical prof " there are always side effects to medication ".

    My advice to you is to go with a conventional solution without shielding and then move it away enough ( sometimes not necessary at all ) to get rid of adverse effects on your tv.
     
  3. Ted Kim

    Ted Kim Stunt Coordinator

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    Buy a shielded driver for the sub, if it's a big concern.

    Also note the sheilding is really for the TV, I don't think it should an issue for the other components, the vibration from the bass being in that kind of proximity can be detrimental to the sonics, if you want to be picky.

    Most speakers can be placed fairly close (about 1 foot, depending on the specific speaker) to the TV, even if they are not magnetically shielded. But, as mentioned before the bigger the driver, the bigger the magnet and the further away it would have to be.
     
  4. Greg Monfort

    Greg Monfort Supporting Actor

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    A plate of 10ga CRS (cold rolled steel) under the TV gets the job done. It needs to be slightly bigger than the TV. I can sit a 2T prosound driver (stronger magnetic field than most sub drivers) on a sheet on top of my TV without it affecting it.

    For L-C-R speakers, 12ga plates inside the cab works too.

    GM
     
  5. AndersP

    AndersP Stunt Coordinator

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    Greg: Is it really true?!!! Woow.[​IMG]
    I´m having a bitch designing my new 3w center, very inspired by the JM-lab Utopia center. I build it with tweeter and mid on top of each other and the woofers on each side of the twmid section. I hav found ok drivers, but nothing shielded for the woofers ( that I can accept ).
    What tv do you have?
    Please tell me more about this because it could save me for a lot of work.[​IMG]
     
  6. ChrisAttebery

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    Well,

    The Sub will be about three feet below my TV. I don't think that will be an issue. I was mainly worried that the sub would effect my DVD, VCR, receiver and Tivo. Actually, the Tivo may be the biggest problem with its internal hard drive, or will the Tivo's steel case shield it? Dan Wiggins from Adire Audio suggested using 10 ga steel as a shield on three sides of the sub. I think I might just glue a piece of 10 or 12 ga steel under the bottom shelf of the entertainment center.

    Thanks for your help,



    Chris
     
  7. Greg Monfort

    Greg Monfort Supporting Actor

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    Greg: Is it really true?!!! Woow.
    ====
    Would I lie to you, huh, would I? [​IMG] While it has low permeability WRT mu-metal, it has a very high saturation point, just what's needed for long term speaker shielding.
    ====
    >What tv do you have?
    ====
    Currently just a Toshiba 27". I had to sell the big screen and some other audio/video stuff to give 'aid' to the 'poor' medical community.
    ====
    >Please tell me more about this because it could save me for a lot of work.
    ====
    What else is there to tell? It's cheap so go get some and prove it to yourself. [​IMG]
    GM
     
  8. AndersP

    AndersP Stunt Coordinator

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    Ok, I´ll do it tomorrow. There closed now.
    Anyway, how thick is 10 ga? I´ve never heard of that unit before. No exact figure necessary, just what ballpark.

    I´m very sorry to hear about the medical community in Chamblee threating your ht-budget. Hope you got your health back. I heard on the news that a lot of it goes to feed a world of lawyers and to " out of court settlements ". It doesn´t work like that in Europe.

    Thanks
    \Anders
     
  9. Greg Monfort

    Greg Monfort Supporting Actor

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    Gauge (gage) is the unit of thickness for metal sheeting here:
    12ga = 0.105" (~2.67mm)
    10ga = 0.125" (~3.18mm)
    There's a tolerance that kept growing over the years and I haven't kept up in quite some time, so actual thickness may be somewhat less.
    Thanks for kind thought! [​IMG]
    GM
     
  10. AndersP

    AndersP Stunt Coordinator

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    I have the plates now and It´s working!!!
    I got one 3 mm and one 4 mm plate and I could not detect any difference.
    I have an old nasty 12´ to test with, so now I can buy the drivers I want.

    Greg: YOU RULE!!!!!!!

    I haven´t had a haircut for months and I try to grow a beard somewhat unsuccessfully and the guys at the steel shop just started their coffee break: I could have it for free if I cut it out myself from scrap pieces they had behind the shop.

    Thanks again!
    \Anders
     

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