Tats1553552671 Posted June 18, 2003 Share Posted June 18, 2003 Has anyone tried to magnetically shield speakers for use close to a TV themselves. I have recently brought a pair of Wharfedale speakers into my HT setup to strengthen the front channels. They sound great however i have had to play around with their positioning to avoid the magnetic interference to the TV and as a consequence they are not as close to the TV as i would like. Any idea's are appeciated even odd ball ones such as a stick on shielding on the outside facing the TV! Link to comment Share on other sites More sharing options...
Tony Davey Posted June 18, 2003 Share Posted June 18, 2003 Buy a front projector with a screen - no shielding issues whatsoever Link to comment Share on other sites More sharing options...
JamesB Posted June 19, 2003 Share Posted June 19, 2003 This link might have some useful information... http://audioworld.com/sw/Forum1/HTML/002830.html Link to comment Share on other sites More sharing options...
Tats1553552671 Posted June 19, 2003 Author Share Posted June 19, 2003 Thanks for the link James, exactly the info i was looking for. I knew there must be a practical solution to a problem that must have hassled many others. For others who are interested here are the basic details for making some Magnetic Shielding. Sourced from JamesB's link. "0.55mm steel, enamel or powder coated to colour with double sided tape on the back!! Really that simple!! Fitted in minutes. Link to comment Share on other sites More sharing options...
Tats1553552671 Posted June 19, 2003 Author Share Posted June 19, 2003 Sorry!! After making the post i realised that i had'nt made it clear that this shielding is stuck to the TV isolating the tube/screen not stuck to the speaker cabinet. I have attached a photo of an example, i'll be giving it a go once i have sorted out where to get the sheet metal. Attached files Link to comment Share on other sites More sharing options...
camdyman Posted June 27, 2003 Share Posted June 27, 2003 having just finished a physics paper on this stuff, i should be able to tell you, but as the exam was last week i have now forgotten it all. I have a problem with magnetic interference from a washing machine behind my computer (on the other side of the wall). It drove me mad untill i put a sheet of aluminium (1mm? 2mm?) behind the desk. Link to comment Share on other sites More sharing options...
Tats1553552671 Posted June 29, 2003 Author Share Posted June 29, 2003 After reading your sugggestion, i thought i'd try some aluminium foil (kitchen type). No good though even folded into 4 layers. The combined thickness must have fell short from what you were usiing or else the magnets in my speakers are generating more interfearence. You must have used aluminium plate of some sort?? I have managed to reduce the green interference to only a 1 Cm square and as it's only noticable on some backgrounds i'm living with it until i get a round tuite (any one got one?!!) Does anyone know if this interferance just looks ugly or can it damage the TV? Link to comment Share on other sites More sharing options...
Tony Davey Posted June 29, 2003 Share Posted June 29, 2003 It can damage your TV. How far away are your speakers from the TV - normally about 1 - 2 foot either side does it. One thing I found once when I had the same problem, was making sure that the speakers were the same distance away from the TV on either side. Dont know why, but it seemed to help. The other thing you can do is unplug your tv from the wall overnight, this can help clear/degause the tube. Sen Link to comment Share on other sites More sharing options...
Tats1553552671 Posted June 29, 2003 Author Share Posted June 29, 2003 Right speaker, against TV! (little interference) left speaker 10 cm. More,interference different angle. I will have to explore some sheet metal for sheilding! Don't suggest a projector, i am married with 3 young children! Still it's a older Sony 29inch (bloody good set in it's day). Maybe i could kill it off and get a 44 inch rear projector!!!! Link to comment Share on other sites More sharing options...
camdyman Posted June 29, 2003 Share Posted June 29, 2003 Yeah, I used some sheet aluminium which i picked up from a metal workshop in Onehunga (the guy gave it too me for free). It has reduced the problem by about 80-80%, A thicker peice would get it all, but as it only affects me like once a week, i can out up with it. Im not sure what sort of metal is best, though the speakers I have must have something like steel plate given their weight. Link to comment Share on other sites More sharing options...
Tony Davey Posted June 29, 2003 Share Posted June 29, 2003 If you physically have the space to do so, you should really move the speakers away from the tube. Even if you shift the speaker that is next to the TV the same distance from the other one, this may help. Over the short term, the speakers will colour the picture tube (usually a green 1/2 moon on the side or in a corner). Over the long-term, this may then grow and become a permanent feature of your TV picture. I would have thought led (spelling?) would have been the only/best material to use to shield your TV from the speaker magnets. Sen And no, I would never want to be held responsible for divorce proceedings arising from the purchase of home theatre equipment (in particular front projectors ) Link to comment Share on other sites More sharing options...
camdyman Posted June 29, 2003 Share Posted June 29, 2003 You can get magnets which you attach to the back of drivers which cancel out the field from the drivers ( eg, http://www.partsexpress.com/webpage.cfm?DID=7&WebPage_ID=3&Start=4&Filter=shielding&searchorderby=1&sm=1&so=1&search_type=198332 ) Another option (probably hard and expensive) Is to get mu-metal (this stuff shields MRI scanners which have McMassive magnetic fields). It is probably very expensive, but I have seen it somewhere online (ill try remember). It comes as a sort of tape which you stick on the insider (or outside) of the speaker box. Im sure that properly shielded speakers just use steel/iron sheet. Although im not sure how this avoids becoming magnetic itself... Could just try a sheet of steel and see what happens. plate steel is so cheap its not a problem if it doesnt work (although im 98% sure it will). Lead will stop the radiation getting out your speakers (If thats where you store your plutonium) but there are better metals for shielding magnetism. If you wanna go the long way, try a google seach for paramagnetism, diamagnetics, ferromagnetism or magnetic permeability Link to comment Share on other sites More sharing options...
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