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.
Edited by spaceloaf (11/03/07 06:52 PM)
Edit Reason: Clarification