SPCR

i need a longer cable for my monitor, was thinking about 3 meters (10ft)... and since my POS monitor doesn't support DVI i need a VGA, or HD15 cable. so... what difference does it make to have a "protected" cable (this is a direct translation from finnish, not sure if it's correct. finnish word is "suojattu.")

the store says protected cables show a better picture. what's this based on? why? how much better is it? and can anything justify its price, which is about triple of the unprotected cables??

Puffi wrote:what difference does it make to have a "protected" cable (this is a direct translation from finnish, not sure if it's correct. finnish word is "suojattu.")

To my understanding "protected" just means layer(s) of shielding (copper braid/foil) wrapped around the cable. This would prevent noise from getting into the signal.

Puffi wrote: the store says protected cables show a better picture. what's this based on? why? how much better is it?

Not sure how "protected cables show a better picture" unless your display already had some noise/interference to start off with. It sounds more of a marketing term to me.

Puffi wrote:and can anything justify its price, which is about triple of the unprotected cables??

I believe most standard vga cables already have ferrite cores on them which serves the same purpose as shielded or "protected" cables.

Is it worth 3x the price for protected? I would say no. I have a standard 5ft regular vga cable (ferrite core at each end) bundled with two ac power cords and I have no interference/noise at all.

To be on the safe side you can buy both "unprotected" and "protected" cables and test them both and see if there is any difference and return the one you don't want.

I'd say that most if not all VGA cables are have protection shielding wrapped around the signal leads. This comes from opening quite a few different VGA cables for modification for use with some prototype devices.

Ferrites simply diminish some frequency bands (depending on ferrite model), they cannot magically distinguish the correct display signal from interference. Therefore ferrites do not help in the same way as shielding that is meant to prevent interference from getting into the analog signals in the first place.

Regardless of the ferrite/shielding issue it is always best to route VGA cables away from devices and cables that are likely to cause interference.

so basically what u're saying it makes no difference to the average user? i mean i've always used a standard cable and i really doubt they've caused any problems. just wondering if this is some new fad i "have to" get into... like if it makes a difference with certain new monitors or whatever...

EMI shielding can certainly make a difference. The question is, will it make a difference for you?

There's a very good reason why "standard" VGA cables are 5 feet long: Any longer and the signal degrades. There's little point in using a shielded five foot cable, as the signal losses at 5 feet are not enough to be noticeable in most cases.

However, as the cable gets longer, the signal gets weaker and more prone to degradation from interference. Eventually, the signal will just disappear altogether and will be unstable or unusable. Without signal amplification, this happens somewhere between 50~100 feet with good quality cables.

A 10 foot cable is still relatively short, so I'd still say that shielding is optional. However, I would still be careful: Don't just buy the cheapest cable you can find; that's a recipe for trouble. You'll have to decide for yourself how much signal integrity matters to you (a degraded signal will look blurry or will appear to quiver). You're unlikely to see any serious problems with an unshielded cable, but you might not want to use it for say, image proofing or colour timing.