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Posted By: FireGuy Lines on Screen During DVD Playback - 11/03/07 02:49 AM
Prior to getting to my question, I've owned Axiom's M3ti's for little less than 2 years. I use them as mains on a 6.1, Celstion F35C center, Polk surrounds and a BIC V1220 sub round out the speakers, all driven by a Denon AVR-1906. I have pondered upgrading to the M22's but just cannot go through with parting with the M3's. They are that good. It's like trying to stop smoking. The thought our not having it around anymore is terrifying. Now to the question: My DVD/SACD/CD/DVD AUDIO is a Yamaha DVD C750. On all DVD's that I play there are vertical, 1" lines that will crawl from left to right on the TV screen. This problem pops in and out during viewing. I initially thought it was an isolated DVD but it happens on all DVD's I run. I'm thinking it maybe the S Video Cable but I don't want to change it out until I've investigated and isolated the problem. Hopefully there is a simple fix. Due to the fact that is occurs on all DVD's it's probably is not the player. Can anyone help?
Posted By: Ken.C Re: Lines on Screen During DVD Playback - 11/03/07 03:01 AM
Odd. I have the same player, but it doesn't exhibit that problem. I'm also using s-vid. One thing to check is if you get the lines on the setup screens. If so, check the cable. If not, it may well be the player.
Posted By: FireGuy Re: Lines on Screen During DVD Playback - 11/03/07 03:08 AM
Thanks. Will do the set up screen test. I'm hoping it is the cable.
Posted By: Mojo Re: Lines on Screen During DVD Playback - 11/03/07 04:25 AM
How long does it take for a single line to cross from the left to the right and has this problem always been there or is it something new?
Posted By: jakewash Re: Lines on Screen During DVD Playback - 11/03/07 04:45 AM
I have found that moving lines are usually the player and color issues are cables, just my rule of thumb, no scientific facts or anything.
Posted By: spaceloaf Re: Lines on Screen During DVD Playback - 11/03/07 10:10 AM
I'm not an expert, but another possibility is that you're picking up RF interference from somewhere. I had a PS2 with similar issues in which I would see horizontal lines whenever I played DVDs on it (games seemed to work fine however).

At the time I was using the stock RCA composite cables that came with the console. Once I upgraded to component cables, the problem went away. The important thing to note is that neither the cables nor the PS2 were bad, but rather there was systemic noise that was affecting the analog connection between the PS2 and the screen.

Unfortunately, there's no guarantee that just switching to component cables will get rid of the problem, since any analog cable will be sensitive to RF interference. The only way to fully rule out RF noise is to use a digital standard (DVI/HDMI).

If you want to be geeky about it though, you could try things like surrounding your player and cable in a Faraday cage, or at least cover the cable in some sort of grounded shielding to see if the problem improves.
Posted By: Mojo Re: Lines on Screen During DVD Playback - 11/03/07 01:58 PM
Yep. That's why I was asking how long it takes the line to cross from one side to the other and if this is a new problem. DVI and HDMI aren't immune to "noise" either and if anything, they may actually be more susceptible. Optics is the only immunity to noise. A Faraday shield won't help if the noise is low frequency like 60Hz.
Posted By: FireGuy Re: Lines on Screen During DVD Playback - 11/03/07 06:25 PM
Everyone's input much appreciated. So you're saying switch the analog S Vid for an optic connection?
Posted By: spaceloaf Re: Lines on Screen During DVD Playback - 11/03/07 10:08 PM
Hi Mojo, you are correct that DVI and HDMI are not immune to all noise, but it is incorrect to say that digital formats are more susceptible to noise than analog formats.

Noise may be more noticeable when using digital since the picture is more perfect (just like M22 speakers are less forgiving to poorly mastered CDs). But the digital format is inherently less sensitive to noise than an analog format.

As long as you're not using cables longer than 15ft, I would be extremely surprised to see any RF noise creeping into a DVI signal. Both DVI and HDMI use differential signaling which should virtually eliminate any RF noise due to cable transmission.

My guess would be people that have noise in their DVI line are actually not picking it up from the cable, but rather from their connection points. For example, if you have a noisy video switch or port (even inside a receiver), it will be injecting noise directly into the cable. At that point there's nothing that any format can do to fix that problem.

Also, you are correct that a Faraday shield may not help extremely low-frequency signals, but I was referring to isolation from station-transmitted RF signals (not signals from space).

Unfortunately, if you're getting a 60Hz interference signal, then it's probably coming from the power line. In that case, you have noise injected directly into the signal, and nothing can fix it at that point. You have to move to a cleaner supply.

As for you R DeVries, there is no such thing as an optical video connection for consumer TVs. Unfortunately, besides upgrading to component or DVI, there's not much else you can do on the cable side of things.

You also might want to try moving your DVD player (e.g. try playing it on a TV in another room, or even better, at someone else's place) to see if the noise goes away there. It's still possible that the source of your noise is from crappy isolation in your player instead of noise from the cable.

Edit: For the sake of science, I should clarify the whole Faraday cage thing. Fundamentally, a Faraday cage can block out any wave that has a significantly longer wavelength than the spacing of the cage links. So there's no reason a Faraday cage can't block out low frequency waves.

The thing is that most low-frequencies in the air come from radiation from space, and are extremely weak (except for the occasional sunspot). If you see a low frequency signal appearing in your system, it is most likely being injected directly into your system through power line, or through some sort of systemic noise in the circuitry. In these cases, a Faraday cage won't help you because the noise is not being picked up from the air.
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