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