How to shield surround speakers from my CRT?

[maggoty]

Howdy,
This is my first post here. I have just bought a sound system. I never had one previously. Amp and speakers. The left and right speakers are as high as the television and sound great, but putting them too close to the set starts to screw the picture up, obviously because of the magnets in the speakers.
Is there a way I can shield either the tv or the speakers, or do I just have to somehow re-arrange my room so that the speakers are well away from the tv.
Any ideas?

Cheers.

[soloist3]

I think they use heavy copper foil to shield speakers; I do not think that it is an easy or cheap thing to do but it can be done. Though I would highly recommend either buying some new shielded speakers or rearranging your room.

[avhed]

I have seen a posting on the internet where it looked easy and cheap. Sorry I do not
remember where it is. How expensive and difficult is it to encase a magnet in a sheet of metal ?

[soloist3]

It sounds like the method you are referring to is the "bucking" method; basically, using another permanent magnet placed in close proximity to the speaker. The problem with this method is that it alters the sound and performance characteristics of the speaker.

The appropriate way of shielding a speaker is by using strong magnetically permeable alloy (usually a copper based alloy). They do sell sheets of this material that you can line the inside of your speaker enclosure with; that would be the next best thing to buying magnetically shielded speakers.

I guess saying that it is difficult may be going too far I just imagine that for some totally disassembling the speaker enclosure and lining it with the material may be a little a bit of a hassle. The money, time and hassle involved may make it easier, and maybe even cheaper, to just buy some nice magnetically shielded speakers.

[Penarin]

I don't think there's much you can do to modify the speakers.

Try moving them out away from the TV, if your room setup allows it.

[DerekinMerrick]

I had the same problem with my Sonyxbr960 and just moved everything away. It worked but 1 out of 20 times I turn the TV on I get the blue dot in the corner I think it has to do with how cranked I have the volume but move the speakers away I think thats the key.

[Spleen]

Go to "lessemf" website to learn how to shield your speakers. I'm a new member here so AVS won't allow me provide you a direct link. Once you are on their site, look for FAQ "How do I shield my speakers." I have not tried their method yet, but it looks promising. You can also google "magnetically shield speakers" and look for them under "Frquently Asked Questions: EMF Shielding."

[ckhirnigs113]

I have a 34xbr960 and it suffers from some type of magnetic interference. I think it may be the central ac system that is behind a wall close to the tv. The farther I get from that wall, the less problem is. I have moved the speakers away to take them out of the equation (they are magnetically shielded anyway). Does anyone know if there is anything I can do to shield my tv from that problematic wall? I don't really have room to put the tv anywhere else. Thanks, CK

[Targus]

I think they use heavy copper foil to shield speakers;

No, they don't.

The appropriate way of shielding a speaker is by using strong magnetically permeable alloy (usually a copper based alloy).

The proper way is to use a bucking magnet. Also, copper is not magnetic, in any way. It's not used to 'shield' against magnetic feilds...mu-metal is.

I think it has to do with how cranked I have the volume but move the speakers away I think thats the key.

No, the field strength of the permanent magnet does not vary with volume.

Move the speakers away from the TV.

[soloist3]

You are right, it is not copper it is usually a cobalt alloy, and, yes, mu-metal does do the job (they use it quite extensively in that regard). I had just heard many bad things about the bucking method, I guess I should not have posted without having all the info.

[G-Bull]

Originally Posted by ckhirnigs113

I have a 34xbr960 and it suffers from some type of magnetic interference. I think it may be the central ac system that is behind a wall close to the tv. The farther I get from that wall, the less problem is. I have moved the speakers away to take them out of the equation (they are magnetically shielded anyway). Does anyone know if there is anything I can do to shield my tv from that problematic wall? I don't really have room to put the tv anywhere else. Thanks, CK

I'd guess that you're right that it's the A/C. The A/C compressor is usually a fairly stout electric motor (I.E. electromagnet) so it has a strong magnetic field. I'm not sure about shielding it, but it's probably not a good idea to have your TV near it. I used to have an old Sharp CRT near a wall-mounted A/C unit in an apartment building. Even now, five years after I moved from that apartment, the TV still has major convergence and color purity problems in the upper-right corner (which was closest to that A/C unit). I suppose a professional degaussing might fix it, but the TV probably isn't worth $20 anyway - it's the kids' TV now, and they don't notice or care...