Hi,

I have a Samsung 26" 1080i Widescreen HDTV, and in my 5.1 setup, my JBL Voice center channel sits on top of the TV. During certain scenes at somewhat high volumes, the TV has very noticable horizontal lines flickering across, or even seeming to "roll" a bit. I was wondering if there's an obvious explanation. It tends to happen only during certain frequencies, because it's always the same parts of source material that cause this. A couple I've noticed:

Return of the King, the oliphants during the Battle of the Pelennor Fields, there are major horizontal line issues. They seem to happen during certain audio frequencies - especially when the oliphants make loud sounds.

Dream Theater: Systematic Chaos DD 5.1 mix. Certain songs also cause this. It seems that loud, higher frequencies (such as guitar solos) have a pronounced effect.

I admittedly don't know much about CRT televisions. Just wondering if anyone has an idea. It seems to happen at higher volumes. The center channel speaker is shielded. Would it be vibrations? The magnet in the center channel? It's weird, because I have a 12" subwoofer within 2 feet of the TV and it doesn't seem to cause any issues at all, so I have a hard time believing it would be a magnetic issue (that center channel doesn't have a magnet anywhere near the size of my sub). Any thoughts would be appreciated. Many sources don't cause the problem, even at high volumes, so I'm wondering what could possibly be the issue with these certain sources. Thanks in advance.

Stephen

Try moving your center channel speaker and see if it goes away. The speaker or its wire may be interfering with the scanning of the tube. Or, your speaker wires may be inducing interference into your video cables. Make sure the speaker wires and video cables don't run close and parallel to one another.

Thanks for the suggestions...I'll definitely try moving the center channel temporarily to see if it alleviates the issue. I just don't understand why it's only with certain frequencies or portions of soundtracks. I wonder if the center channel has vibration issues or something. I might see if I can get a bookshelf speaker to put on top as the center channel instead and see if that works too. If anyone else has ideas, feel free to chime in :).

Don't you love this? my "shielded" speakers used to cause problems with my old set a while back. Guess they weren't shielded enough to be close to the TV! Must have wanted me to put my center speaker on the floor. This is the worst part of home/audio in my eyes. Having to configure/move every part of your equipment/wires to play nice. Seems like everything can and does cause interference.

I also had my center speaker on top of the TV then and now have it under my new set. I'm not sure vibrations would cause any interference, especialy since you say it only happens and certain frequencies. Does your speaker wire run behind the TV set along the back of it by where the AC plug is? that could be the problem. I would try moving the speaker under the set and see what happens. Also if you just have your center directly on top of the set you might want to put some rubber door stops, or something to help with any vibrations, cause even if it's not the vibrations you don't want it to fall off the TV!