Magnetic shielding

My AVI Pronines has no magnetic shielding and putting it near to TV causes the picture/color to goes into crazy distortion. These is a purely for self education. I believe the only way to shield the loudspeaker magnet is to pair it with another matched magnet? Not some thing one could do easily I imaging?

 

Put a sheet of copper between the two. 0.050" thick should be enough (PCB blank, available from maplin).

 

Move them away from ther telly

 

If you take a similar magnet, press it against the first (positive to positive or negative to negative) and wrap a can around them both, you'll have a screened speaker.

A secondary advantage is that the efficiency will go up by a dB or two.

Quite easy if you can get the magnets.

 

get a plasma telly

 

Na LCD, Plasma is so early millenium.

 

Plus its snob value is inverted, does that count?

 

Thanks 7V for the explanation. As expected it does require opening the speaker cabinet.

Seems like your suggestion to replace the picture screen is a better idea. In fact I think I might put the loudspeakers closer to the TV in the next few days. I should even blonk one on top of the screen and then show her that the TV is trully broke. It is time to replace it with one of those flat bigger screen. Has LCD and plasma screen caught up with CRT in terms of color/constrast accuracy yet? Upgraditis is an incurable disease.

 

New LCD is pretty good colour wise, if you sit too close then slight graining compared to CRT, but mine is 26" JVC model, sits on the wall, and looks great, leaves more room in cornewr for Hifi, whatever you do Wolfgang, don't buy from shop they are much cheaper on the net, go to shop for a look at the different models though (cheeky, I know but comet can afford it).

 

The only one I would consider buying is one of the new Panasonic Plasmas. CRT has a typical contrast ratio of 4500:1, the Panasonic Plasmas have a ratio of 4000:1. Most other plasmas have contrast ratios in the 1000:1 - 2000:1 range. LCD contrast ratio is typically about 500:1.

Panasonic also appear to have impoved the expected lifespan of their plasmas.

Heath

 

Yeah but if telly is your less preffered route to home entertianment then VLCD are good enough and they have a lovely colour balance. Oh and are smaller cooler and cheaper, and don't need expensive refills, I say leave plasma nad projectors to the real film buffs everyone else will be just as happy with LCD

 

AK,

This, I am afraid, is an urban myth spread about by clueless sales guys in high street shops. Think about the construction of a plasma. It would be impossible to refil the gas, even if it did diffuse through the glass which it doesnt.

 

Heath I'm afraid the Poineer 503HX has a constrast ratio of 9000:1 however I'd take my LCD anyday over it (and I have both)
The new NEC 61" Plasma is getting better, but they're still a long way off being right.
Maybe in year or 2 the right technology will come along

 

Well Robbo what is it thats done when recharging, a friend of mine had his taken away for a week to recharge, or was it just repair?, I'm kinda ignorant when it comes to tellies I knew the "tube" was sealed but I just assumed it had a valve or some sort on it. Please elaborate

 

Are you sure that's not a misprint - I thought the Pioneer 503s only had a contrast ratio of 900:1, ie poor, even by plasma standards. The new 505s only have a contrast ratio of 1100:1.

I recently saw a comparison of the latest Pioneer and Panasonic plasmas - the Pioneer was much more user friendly and had a better range of connections, but the Panasonic completely blew it away for picture quality.

Heath

 

Hi AK,

I have done some searching to find some information for you about how plasmas are constructed. Take a look at the site which I think is very informative.

http://www.plasmatvscience.org/technology.html

As you can see a typical plasma is made up of tens of thousands of little cells containing xenon and argon fused between two glass plates. (this is done by manufacturing the displays in an atmosphere of the gases I believe). As the cells are sealed and cannot be re-opened (as the glass sandwich is fused together), I welcome any suggestions as to how the cells can be re-gassed (bearing in mind that you cannot diffuse the gas through the glass). Answers on a postcard please.

Cheers, Robbo

 

You can however, keep warm in front of a plasma screen. Get a DVD of a log fire, and many people will be fooled.

In fact, it chucks out so much heat and IR that if you stand in front of it and have some devices close to it that have IR remotes, enough IR from the screen will bounce off you to make the devices go crazy. Yes, I've done it.

 

Heh Robbo I'm not arguing with you just curious, have heard all the myths and not being in the market for a plasma screen I had no reason to disbelieve the rumours, this will be nice to know for pub arguments etc, I can believe salesmen running with the scare stories but my mate was told the same thing by his dealer, who subsequently removed the screen and took it away to be "recharged" technicians words not mine, with you contradicting this i can only assume that there was some other fault with the screen as it came back and was working fine, I wonder if this is a ploy to charge more for what was prolly an easy inexpensive repair.

 

Sounds like the dealer has got a good scam going on! If it was me, I'd ask the dealer to explain exactly what they do when a screen is 'recharged'

 

Accoring to this pioneer datasheet, the contrast ratio for the 503 is 900:1.

http://www.av-sales.com/plasma/Pioneer503mxe.pdf

Cheers, Robbo