Texas Instruments makes a heavy metal material called TI shield, it is designed to do just what you are asking about. It is available from Mike Percy audio products. If I remember correctly, I paid less than $20.00 for a one foot square section of this. You can download a PDF file of all the data at his web site: http://www.bainbridge.net/percyaudio
How to magnetically shield a speaker????
Help needed!!! Does anybody know how to magnetically shield a TV placed right above the floorstanding center speaker? The TV is on a firm movable platform (can go up to 4 feet high) with my center speaker right under it. I haven't chosen a projector yet, so I'm going to use my TV meanwhile. I saw a couple of links on this subject where they recommended to put the TV/monitor in a metal cage - quite a horrible vision to me. Is it possible to to obtain the same results using some thin foil or sheet? Thanks in advance. Mike.