I'm confused about shielding. (1 Viewer)

[KellyR]

When I think of shielding, I think of higher end wiring that has te rubber coating and the sheidling underneath. I thought that when people on the forum were talking about shielding, this was what they were talking about until someone mentioned having their speakers shielded. Can someone explain shielding to me. Thanks.

 

[Chu Gai]

Your speakers have magnets and this field varies as the speaker is played. The varying magnetic field that is generated can interact with the picture shown on your TV. Speakers that are shielded prevent this interaction from occuring hence you can place your speakers close (like the center channel on top) to your TV without any degradation of the image. If you've got a very strong magnet, you can observe this by moving it close to your TV. Very oversimplified.

 

[KellyR]

And wat can be done (besides moving the speaker further away) to remedy the situation?

 

[Jeff Gatie]

And wat can be done (besides moving the speaker further away) to remedy the situation?

You can buy shielded speakers. Most speakers designed for Home Theater come shielded, certainly any speaker billed as a "center". This is not much of a problem with regular HT speakers, but it does raise an issue if you want to place your subwoofer close to your TV as most subs are not shielded.

 

[JamesCB]

and this field varies as the speaker is played

Chu, I thought the magnetic fields were present whether the speaker is active or not. Do the fields change as the speaker is in operation?

 

[Chu Gai]

It certainly is present as at all times and when the speaker is played it also varies. Hey, it was a quick answer on the first cup of coffee! Now who knows what they use for shielding?

 

[brentl]

You can also shield your speakers if need be!

Brent

 

[Cees Alons]

They may use metal (preferably mu-metal) for shielding, but they also use (an)other magnet(s) to counter the speaker's one.

And although the field around the coil will indeed vary as the driver is played, I don't think the field of the big magnet, which is what disturbs the TV, will change noticeably.

And, Kelly, of course you were right about that wire.


Cees

 

[ChrisWiggles]

Shielding for wires and speakers are both shielding, just for different purposes. Wires can(and do) emit interference, but it's very very small for interconnects. Their signal is very small, and susceptible to outside sources of interference affecting the signal. This shielding, such as in a coaxial cable keeps interfering fields OUT of the wire. The speakers are shielded so they dont emit as much and mess things up that would be particularly susceptible (usually CRT TVs.)