Gary W. Graley Posted March 16, 2002 Share Posted March 16, 2002 I have the RC7 for almost a week and noticed on the top right corner of my Sony 27" tv some pull or dark mark in the corner, I put some aluminum foil beneath the speaker to help if that is what is causing the problem, the speaker rests on top of a wood shelf and that is about 3" above the tv as well as being about 3/4" thick...I wouldn't have expected that to do that, has anyone else noticed a problem with this center? Later on when I upgrade to a larger tv, I'll have to rest the RC7 directly on top of the tv and worry that it may really pull more, if indeed the speaker is causing this on the tv...there is nothing else near the tv that could cause this, before I had the RC3 and before that, no center at all...My RF7s are to the side a few feet away... Thanks, G2 This message has been edited by Gary W. Graley on 03-17-2002 at 01:49 PM Quote Link to comment Share on other sites More sharing options...
TheEAR Posted March 16, 2002 Share Posted March 16, 2002 Strange,I have a RC-7 also and it sits on top of my Toshiba and its A ok.No purple distortion,no problems. Are you sure you dont have some other speakers next to the TV? The RF-7's and RC-7 are shielded to divine perfection,in my case anyway. TheEAR(s) Now theears Quote Link to comment Share on other sites More sharing options...
Gary W. Graley Posted March 17, 2002 Author Share Posted March 17, 2002 TE, nope nothing else is near the tv at all, so it is strange for sure, the foil didn't seem to make any difference but it may be a permanent problem or it will take a while to clear up? It isn't BIG but it is annoying to see, as the rest of the tv plays great. You can only see it when a white area is being put on the screen. The speaker is pretty darn heavy, I've removed the speaker just now to see if it went away and nope, still there, so maybe its a problem with the tv itself? My RF7s are about 2' away from the side of the tv, my receiver, Sony 840 is to the side of the Center channel... This may have been a long standing problem as when I play DVDs the black bars are along the top and that isn't visible then, regular tv programming or some Disney full screen features made me notice it with in the past few days, but I am pretty picky about such things and surely would have noticed it before so I worry that the RC7 has induced some trouble, the speakers in that must have nice big magnets on them, what does Klipsch use for sheilding? Could mine have missed that step in the assembly process? RC7BK 01440277 is the serial number on this unit and it was made very recently I am told... G2 This message has been edited by Gary W. Graley on 03-17-2002 at 10:52 AM Quote Link to comment Share on other sites More sharing options...
pierceb Posted March 17, 2002 Share Posted March 17, 2002 Gary, I'm suspecting a similar problem with my RC-7. I have a Panasonic 32" GAOO tv, and the RC-7 is mounted on a shelf about 3" above the tv. The picture colour is not affected; however, the picture is somewhat distorted (if you look at a square box, it has an hourglass shape). You don't notice it too much during action, but when credits role, or you go to setup menus, you can really see it. I never even thought it could be the speaker causing this because I've had numerous other problems with the tv, and I thought the speaker was fully shielded. I will pull my tv away from the speaker today (big production!) and see if it fixes the problem. -PB Quote Link to comment Share on other sites More sharing options...
Malcolm Posted March 17, 2002 Share Posted March 17, 2002 Sounds to me like you may have magnetized part of the shadow mask on your picture tube. Perhaps one of the woofer magnets came close to that spot when you were placing the speaker on top of the set. As TheEAR points out, they are very well shielded. But the shielding is not absolute. And, it doesn't take much of a magnetic field in the right place to cause a problem. I have seen a child do this by trying to stick a small refrigerator magnet on the screen. Your TV's degaussing circuit may take care of it over time. Or you may need to degauss the tube. BTW aluminum foil won't help you with magnetic fields. Quote Link to comment Share on other sites More sharing options...
Gary W. Graley Posted March 17, 2002 Author Share Posted March 17, 2002 quote: Originally posted by Malcolm: ....BTW aluminum foil won't help you with magnetic fields. Nuts, I was afraid that the foil wouldn't do much if anything, guess I can take that off and go wrap a roast or two... I noticed today that the THX logo has an hour glass shape to it now so I think it may have something to do with the speaker? TE is your tv a tube type? G2 Quote Link to comment Share on other sites More sharing options...
Deang Posted March 17, 2002 Share Posted March 17, 2002 how does one 'degauss' a picture tube? ------------------ dean Quote Link to comment Share on other sites More sharing options...
Malcolm Posted March 17, 2002 Share Posted March 17, 2002 The easiest way to degauss a picture tube is with the built in degaussing coil in the set. I think just about all sets nowadays have them. It gets powered up for a short time when you turn the set on. If that doesn't do the job, something more powerful is needed. A bulk tape eraser moved quickly back and forth across the screen can sometimes do the job. Otherwise, you may need to use a degaussing coil purpose built for the job. They are not much more than a coil of wire plugged into the wall outlet. Used to be a standard tool of the trade among color TV techs. Don't know how common it is today. Don't know where you can get one. You could roll your own, but I don't have the specs. There is one other way to degauss a picture tube. But I don't think anyone would want to use it. Hit it real hard. Anything that has been magnetized can be demagnetized by hitting it hard enough. Quote Link to comment Share on other sites More sharing options...
Malcolm Posted March 17, 2002 Share Posted March 17, 2002 http://starkelectronic.com/gc9317.htm Quote Link to comment Share on other sites More sharing options...
pierceb Posted March 18, 2002 Share Posted March 18, 2002 Well - I pulled my tube away from my ht equipment for the most today to see if the tube would deguass itself after a while. I turned it on, then off, let it play for couple hours, turned it on then off again with long and short pauses, and so on. There was no difference in picture quality at all - none. I have had nothing but problems with this TV, Panasonic, and the dealer since brand new, and I'm sick off fighting with these guys. Their customer service sucks in Canada, I've never seen such bad service! In summary, I don't think I'm getting much interference from my RC-7. Maybe I didn't give it enough time, but after a few hours away from the speaker, I couldn't notice any difference. -PB Quote Link to comment Share on other sites More sharing options...
Malcolm Posted March 18, 2002 Share Posted March 18, 2002 The degaussing circuit operates only for a few seconds after turning on the TV. You will see any improvement in that much time. I would not blame the TV if the shadow mask is magnetized. All color direct view sets have the same potential problem because of the steel shadow mask in the picture tube. Get a strong enough magnetic field close enough to the mask and you will have the problem. The degaussing circuits in the sets aren't really design to undo this kind of damage. So, you may need something more powerful. There is another potential problem. It is possible for stray magnetic field from the speaker to affect the picture even if it is not strong enough to magnetize the shadow mask. If this happens, the problem will go away, or change, when you move the speaker. Is it possible that the problem existed before you put the speaker on top of the set and just didn't notice it before? If so, there is another possible cause for this kind of distortion. Your set may just need alignment. If you have had the set for a long time, it is possible component values have drifted. In addition to that, sets are aligned at the factory based on a nominal magnetic field for the area in which they are to be sold. Unfortunately, almost nobody lives in this nominal magnetic field. Most get by OK. The farther your environment is from nominal, the worse the picture. Those who live near magnetic anomalies may have the worst pictures. The fix is to align the set where it is going to be watched. In the early days of color TV, when a service technician actually installed the set, this was part of the setup procedure. Quote Link to comment Share on other sites More sharing options...
pierceb Posted March 18, 2002 Share Posted March 18, 2002 Thanks Malcolm, Yes it is likely the set had the problem when it came through my door. I always suspected this; however, seeing Gary's problem I thought maybe it was the magnetic field from the speaker. I just never tried pulling the speaker away as I assumed it was fully shielded. I had this problem with the TV when I first bought it, I sent it back to the repair shop 3 times and to Panasonic once; and still had similar (and different) problems. Each time the set came back, the distortion was different, or there was no colour. Fianlly, I demanded a new set, and after lots of complaints by Panasonic, they finally brought a new TV to my home. Now it has this hourglass shape (it actually changes as the picture changes). This was supposed to be their top of the line TV. I just want to take a sledge hammer to it. I will never, ever buy Panasonic again! -PB Quote Link to comment Share on other sites More sharing options...
Grimer Posted March 18, 2002 Share Posted March 18, 2002 I'm having similar problems with my new 36xbr450. I bought a guass meter from lessemf.com and have narrowed the problem down to my receiver and other components which are about a foot and a half above the tv. the meter won't detect the speaker, but I think it's a problem too. Foil definitely won't work. I'm going to buy a product that they have called MagnaShield. It's a MU-Metal that will block offending sources. It's really thin, so you can mount it to a board and place it under your speaker, or under your components which are interfering. I never thought this tv would be this sensitive, nor did I know that components could interfere. I thought guassing was just caused by speakers. Anyway, hth. grimer Quote Link to comment Share on other sites More sharing options...
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