Why aren't all speakers shielded? Please explain shielding to me...

Discussion in 'Archived Threads 2001-2004' started by Jeff_M, May 16, 2002.

  1. Jeff_M

    Jeff_M Stunt Coordinator

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    Could someone explain what is involved in shielding a speaker so that it can be used near a tube-based television? Why aren't all speakers shielded? Is there an actual change in the components of the speaker involved? Any adverse effect on sound? Why does it often cost more to buy a shielded version of a speaker? I am completely in the dark on this one and would appreciate any of your kind expertise!
     
  2. Ned

    Ned Supporting Actor

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    Simple cost-cutting. Shielding requires bucking? magnets to shield the stray magnetic fields. No sense putting them in every speaker you make when most won't be near a tv. What sucks is that many companies do not offer the option at all so you have less choices sometimes (hello B+W?)
     
  3. Eric_M

    Eric_M Stunt Coordinator

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    What would be the safest distance for most speakers to be away from a TV to prevent any sort of interference. I am wondering so I know wether or not it is worth that extra money or not.
     
  4. Drew Eckhardt

    Drew Eckhardt Stunt Coordinator

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    I ran my (unshielded) main speakers 7-8' apart when I was using a 32" Sony Wega with no problems. Given reasonable main speaker placement, I don't think you'll have problems.

    Of course, front projection makes the problem go away :)
     
  5. Ned

    Ned Supporting Actor

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    It depends on the tv. My regular KV Sony 27" seems very susceptible to magnetic fields. My B+W's are 18" from the edge and they still show a little smearing. The same speakers at the store had no effect on a Toshiba set even right beside.
     
  6. Ash

    Ash Auditioning

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    A good idea to clear the smear is to switch off the tv (not keeping it on standby mode) a few nights a week. This allows the tube to degauss.
     
  7. Eric_M

    Eric_M Stunt Coordinator

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    Drew,

    You mean each speaker was 7 - 8 ft away from the TV?

    I ask as I am considering the 32 inch Wega set also(the FS13 model) and I will most likely end up with Monitor 7s or Minis and wonder if it I can just get the unshielded and be fine. My speakers would be set about 3ft away from the set.

    Another quick question to anyone, when you buy unshileded speakers, is it possible to shield them later on if need be?
     
  8. Michael Marklund

    Michael Marklund Stunt Coordinator

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    Jeff,

    If your speakers (mains) will be very close to your tv, you will pretty much need to go with shielded speakers. The shielding keeps the magnetic field from skewing the color on your tv. Direct view tv's are more susceptible than rptv's, but even when I emailed Mitsu about speaker placement next to my rptv, they said an unshielded speaker had to be at least 1' away from the cabinet.

    Shielded speakers cost more b/c there's slightly more to making them. When I looked at Paradigm, the shielded ones ran $60.00 more than unshielded. Most speaker company websites will indicate shielded/unshielded in their tech specs. Between that and input from HTF members, I was able to come up with quite a list of speakers to chose from that were shielded.

    Probably the best example of the need for shielding is in center speakers. As these are almost always placed on top of one's tv, they need to be shielded. And you'd be hard pressed to find a center speaker that's not shielded.

    If you need help finding shielded speakers, do a search on this forum for shielded floorstanders that was running about amonth ago.

    Regards,

    MM
     
  9. Steve_Ma

    Steve_Ma Second Unit

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    My 32" vvega also seems quite suceptible to magnetic feilds. My B&Ws (603S2) NEED to be at least 16-18" away. Oddly enough....my B&W sub (ASW1000) is sheilded. I never knew this till I got a new TV/stand and was able to experiment with different sub placements for better audio. I now have that sucker right next to the TV with no probs. It's a good thing too, as right next to the TV is clearly the best place for the cleanest sub response. As long as I'm stuck in that odd a#$ room, any sub I buy will NEED to be sheilded [​IMG].
    --Steve
     
  10. Eric_M

    Eric_M Stunt Coordinator

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    Would you be able to shield speakers later on if need be?
     
  11. BrianWoerndle

    BrianWoerndle Supporting Actor

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  12. Drew Eckhardt

    Drew Eckhardt Stunt Coordinator

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