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The best way to shield components from each other?

I need solid, reliable info on how to shield different components from each other, mainly what material(s) works the best.

I have a fairly small room (about 12' wide at the equipment end) so that when all of the gear is lined up across the front of the room, then the Mitsubishi 40" CRT TV shows extremely distorted colors on the edges and corners that are closest to the other gear. On the left of the TV is an enclosed maple bookcase/equipment rack and to the right of the TV is the worst interference, a Velodyne HGS-12 subwoofer. It begins to distort the TV when it gets within 3'! If placed next to the TV then at least half of the picture is wierded out. To the left of the equipment rack and to the right of the sub is a pair of B&W N802 speakers, that are supposed to be already shielded. If the sub distorts the TV that much then it is probably also distorting the 802 speaker.
On top of the TV is a B&W HTM-1 center channel speaker that does not distort the TV, so it must be shielded with the proper material to not interfere with the TV.

I was going to have a cabinetmaker friend build a 3-sided maple plantstand/box to go over the subwoofer so that it can be placed next to the TV, but it needs a shielding material inside of the box because the maple itself will not provide anywhere near enough shielding on it's own.

I was told by my local retailer/guru in Boulder that a non-ferrous metal such as aluminum would shield without causing interference to the electromagnetics of the sub, but I know that aluminum does indeed conduct electricity. Another person who is an engineer said that aluminum would not work.

Questions:
1. Can anyone tell me what material is used on the inside of speakers by most speaker manufacturers to effectively shield the speakers ?
2. What is the best shielding material to keep components from interfering with each other but does not compromise the performance of the components?
3. Is it necessary to use the same material inside of the component rack (such as on the bottom of the rack shelving) to shield components from each other? The rack contains a Denon AVR 5800 receiver, a Denon POA-5200 2-channel amp, an SCD-1 SACD player, a Pioneer DV-05 DVD player, a Pioneer LD player, and a Monster HTS-500 power supply/conditioner.

If anyone can answer these questions or direct me to someone who can, then your help is greatly appreciated.

Thanks. Robert. Boulder
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abstract7
541 posts
 
There is a material called TI shielding. You can get it from Percy Audio.
http://www.bainbridge.net/percyaudio/
I've used it between components (particularly my tube phono stage which is highly susceptible to noise and interference). It works well. It's kind of expensive. Some other people might have some cheaper solutions. One word of caution, is magnetic shielding can be somewhat problematic, because the fields are not linear and can go around shielding. It depends on the strength of the magnet and it's spacing to the shielding. Speaker manufacturers have built appropriately shaped enclosures with appropriate distances around the magnet that nearly eliminates the field. Once you've figured it out for a particular magnet it's easy to do--but might take some experimentation the first go around.
herman
2,273 posts
 
Some (most?) shielded speakers are not actually shielded due to the afore mentioned difficulties in constructing an effective magnetic shield. The trick is to take an additional magnet of equal strength and align it in the cabinet so the magnetic lines of flux from the speaker magnet flow to the second magnet and are more or less contained.

Bob Merrill from Underground Sound in Memphis made a shelving system consisting of very heavy metal shelves that he claimed provided the component shielding you desire. Last I checked he had a few left at very reasonable closeout prices.

http://www.merrillaudio.com/stabletableii.html
drjjpdc
80 posts
 
My room width is similar to yours, and my solution is the easiest. Try the sub between your front speakers and in front of the TV. That's the way many theater set-ups do it. My sub fires to the front. Just put it about 3 or so feet in front of the TV. Your front speakers should be wide enough apart to accomodate this set-up. My sub actually sounds best in my room this way. Don't worry about mucking up any image stuff between your front speakers, they should sound just fine. BTW I have B&W matrix 804's.
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