Originally Posted by Bob Pariseau
Gill, it's impossible for the cable to send a pixel value which will make the display produce a blacker black than what it always does when it receives a "black" pixel. A black pixel is just a certain numeric value and the physical limitations of the display control how little light gets output for each "black" pixel.
This means if you were seeing better picture results for the new cable -- "blacker blacks" in particular -- then the old cable MUST have been screwing up.
Now, bit-drop errors are certainly possible in an HDMI run -- particularly a long one. I.e., the handshake can complete without problem, but the video is still corrupt. However, there is a vanishingly small chance that the error will always be in the low order bit or 2. Bit drop errors in pixel values will be dispersed across all the bits in the value.
And that means that video corruption is always easy to spot if you look for it. It is not subtle.
The classic symptom is "the sparklies" -- widely scattered pixels of obviously the wrong brightness or color, flickering in and out of visibility. These are most easily spotted in black or near black portions of a scene, but actually exist across the entire image.
It may very well be that your old cable had a failure like this -- perhaps not when you first installed it, but one that developed over time due to lead corrosion, or whatever. If you didn't get right up to the screen looking for problems, you might easily have missed it when they showed up and just got used to the corrupted imaging as "normal". But if you are seeing an obvious video improvement with the new cable, then the old cable ABSOLUTELY MUST have been producing video corruption, which would be obvious if you went to look for it.
Let me preface the following by stating that we have only the highest regard for your observations. We’ve learned from you and shared info for several years here on AVS. In particular we remember when we all thought the PQ on the 93/95 was a hair better than on the 83 on Blu-rays which supposedly isn’t possible.
Our observations about the difference we saw with a standard 50’ HDMI Monoprice cable and the 50’ RedMere are these. The blacks were blacker and everything had more of a wow factor with the RedMere meaning sharper with color more “film” like. Since my partner is a video “nut” (I’m the audio “nut”) he constantly is evaluating the PQ through our projector down to the pixel level. Therefore, we think he would have seen “sparklies” but maybe not.
However, with your observations and those of VRDnhors (post #2144) offered earlier let’s get the exact setup of the cables laid out so to speak. During the evaluation the original cable was laid behind a cabinet with A/V gear and then next to one with audio gear following the wall/floor boundary including behind a stack of power line conditioners and across a stairwell to the projector. The RedMere was laid across the middle of the living room floor on a carpet from the Integra A/V receiver.
As was pointed out by VRDnhorms the position of the wires were different. As both of you pointed out the solder joints could be bad or have deteriorated leading to a weakened signal. However, with our limited understanding of the transmission of digital (as opposed to analog) data you either get it or you don’t at the receiving end.
However, from your description it looks like it must come down to some type of “video corruption” at work. We guess we’ll never really know as we took out the old cable and replaced it with the new cable in the same run. So, we’ll just have to live with the better PQ whatever the reason. As usual it all comes down to “enjoying the video” (or music).
Under “clear and it might hit 30 tonight!” Seattle skies, Gill
P.S.: Thank you David (dmusoke) & jimshowalter for your later postings helping to educate.