Is there a difference in HDMI cables?

kuntasensei

If by fiber optic, we're talking about TOSlink, then no; nor did I say that I think all HDMI cable is the same. But the two things are not an apples to apples comparison. There is some error correction with SP/DIF interfaces as far as jitter goes, but there's not built-in error correction in DD/DTS codecs being passed over same that ensure bit-for-bit reproduction - just signal and clock. With TOSlink, data loss results in obvious audio artifacts, usually loud annoying pops. I'd imagine that's why the muting for extreme data loss was implemented in the lossless codecs.

HDMI is a different beast, and is designed for all-or-nothing when it comes to lossless audio and HD video. Even with the lossy codecs like DD/DTS, the 34x increase in bandwidth over TOSlink virtually ensures that you're going to end up with the correct information at the endpoint, though I suppose with the lack of error correction inherent in those codecs, it is possible (however unlikely) that you could have audio artifacts related to data loss in those cases. Contrast that with the lossless codecs where it is impossible by design.

So again, I ask... What audio/video artifacts are people claiming a bad cable could exhibit?

kuntasensei

tonyb wrote: »

It still gets the signal from point A to point B but just does a crappy job doing it.

I want to clarify that I'm not saying certain cables aren't better constructed or hold signal strength better than others. That much should go without saying. My point is that in the case of HDMI, even if the cable does a crappy job doing it, it can't introduce the video artifacts we're used to seeing with analog video that people are describing (i.e. an increase in clarity or being more vivid/less dull). If you're not seeing sparkles denoting intersymbol interference or complete blanking denoting data packet failure, you're getting the same picture regardless of cable quality. Same goes for the audio side as previously explained. This isn't a matter of whether someone has tried it for themselves... it's the science behind the interface and transmission method, and is by design.

Not making a mountain out of a molehill. The OP tried better cables, he perceived a difference (even if we know it to be placebo), so it was money well spent for him. But telling people that an HDMI cable can create differences that are scientifically impossible deserves some discussion, which differentiates this from the typical debates over analog cables and their effect on the end result, and I'd still like to know what artifacts those on that side of the argument are claiming were cleaned up by the better designed cable.

ft_townman

I guess i should have expected a huge debate over this topic. Thanks to all who put in there 2 cents. That's all i am doing. I simply had to see if there was any difference and regardless of what anyone says i could definately see one. A lot of what everyone said kind of went over my head. I'm no genius in this department, I just love home theater. I never said anything about sound improvement as i just hooked it directly into the tv. All i was looking for was picture quality. I respect a lot of what was said by everyone whether i agree or not. That's what makes this site great so people like me can learn. It's trial and error as i don't have any local friends this into home theater that can teach me. all i have to say is the main improvement i saw was the flawlessness of the picture. with the cheaper cable it seemed a slight blur was around fast moving objects and those crystal looking affects you guys talked about. When the cinnamon was plugged in that all went away. Thats what i seen. so yes i would rather satisfy my soul and buy decent cable as opposed to the crappy one. i could care less what the difference is between a monster cable and any other high end brand. I think most would agree theres not much difference between good cables and great cables without getting some tool that can hear or see things we can't. from there its about brand choice and to each there own if u ask me.

cnh

I'm going to have to say the Kuntasensei has some points above and a close friend of mine in the film/video business, editing, producing, mixing, etc. would probably agree with him on this. I know I run a variety of HDMI cables and I can't see the difference, myself. Personally, I am not against a more objective testing of HDMI cables. I'd like to see that. Because there are a LOT of items besides HDMI cables that can affect the quality of an HD picture in your "chain". The processing is really done by other pieces, the bits are passed through the cable. (Now a cheap-cable made of a Chinese lead alloy may be a problem, lol, but a decent quality cable?)

I do, though believe that for "other" cables, there are very noticeable differences between low quality and high quality cables. One also has to "wonder" out loud about what kind of "wiring" we find inside the PCs that are USED to visualize and edit the VIDEO and FILM footage we display on our HDTVs, where video cards, processors, and RAM memory, etc. reign supreme and there is not much of a discussion of other items.

Not particularly interested in flaring anyone up here. I'm just thinking out loud, that's all.

cnh

polkfarmboy

Well for me I have a JVC X30 with the best contrast in the biz and and Anthem D2 hooked up to the most accurate ( not best)ML speaker tech and if I cannot tell the diff between a pricey wireworld and a mid level audioquest then how much more do I have to spend to see a difference?

Its all a bunch of crap to me and warrants nothing about a serious discussion, I am not a cable nay say'r either

ZLTFUL

My point was merely a comparison of materials. Steel conductors are far more prone to failure than OFC or silver. Steel oxides at a much faster rate so if there happens to be ANY moisture content inside the jacket, steel *will* fail.

I was not debating the hows or whys of the signal. If a cable meets HDMI specifications, it will do the job. The rest is just marketing hype. Personally, I prefer to spend a little bit more money on a cable that I know comes from a reliable manufacturer as cheap insurance against getting some random cable that may or may not work the next time I move something attached to it.

polkfarmboy

Monoprice cables have failed me everytime as I swap cables out often and they just cannot take it. I remember when I had an Onkyo avr and the heat would melt the connections out of the housing at the ends. They also break in the lines too so no more of those and it was my reason to step up in price

kuntasensei

Well said, ZLTFUL. In my case, I was glad (and a little surprised) that the heavy-gauge Monoprice cables I used in-wall managed to work for my projector run with no issues, even when fed 1080p 36-bit color from my Oppo to my AVR and then across the long run in the wall. That makes total end-to-end cable length from the source about 30-35 feet, with wall plates and connectors in the mix. I had actually bought an in-line equalizer to counter the length of the run, but as it turned out, the equalizer gave me sparklies whereas the straight run gave me no issues.

tonyb

ZLTFUL wrote: »

If a cable meets HDMI specifications, it will do the job. The rest is just marketing hype.

"Doing the job", as you so put has different levels of acceptence. Is it not possible 2 cables can both "do the job" yet one does it better than another ? Possibly resulting in differences in sight and sound ?

headrott

kuntasensei wrote: »

Well, I wasn't gonna go that far... but with how HDMI works, claims of "crisper, cleaner and more vivid" are technically impossible. For there to be that kind of a difference, interference of some nature would have to be able to change 1s and 0s... which simply can't happen. You can have a rounding off of the waveform from a cheapo cable... but that doesn't affect picture quality, because the endpoint data is still the same. And if it ISN'T the same (i.e. fails the error correction checksum), then it simply doesn't get displayed AT ALL. There can't be a change in resolution or color because these are digital values, dependent upon the display's reconstruction. In other words, a color value of Red 240 will either be Red 240 or nothing... so a cable can't possibly affect how "vivid" the end result is. The signal strength isn't what assigns the brightness of the color. By the same token, it can't change the black/white levels or sharpness at all.

But again, if people perceive a difference, then it's worth the money to them. Who am I to argue? (And no, I will not take your Emo-bait, sir! Heh...)

The old 1's and 0's adage. The only thing is, how much is the 1's and 0's adage based upong real observation (using the senses) instead of electronic equipment? Why is it that some believe that electronic equipment can measure everything there is to measure in the digital realm?

The idea that if the signal gets there it is displayed in the same quality regardless of what metals, dialectrics and construction of the digital cable is hogwash. You are saying that if the signal is high enough quality after transfer through an HDMI cable then it is displayed exactly the same regarless of the cable dialectrics, metal(s), and configuration. I would argue that ALL things affect even a digital signal. Mostly the transfer speed and jitter induction have a large affect on this digital signal, and these are affected by the factors I mentioned above. To say the signal is exactly the same at the end of ALL HDMI cables is preposterous for the reasons I mentioned above. More jitter means lower quality and slower speed means lower quality. I do realise there are minimum speed required and designated by what version of HDMI cable is designated as (1.3c, 1.4a, etc.etc etc), but these are minimum acceptable levels to be designated as an HDMI 1.4a cable etc. If a cable exceed these minimum levels (as I brought up due to reasons above) then why would this cable with higher standards (than the minimum) not have a better picture quality (resolution, color, etc.) than a minimum quality level cable? The same goes for the digital audio signal sent through the HDMI cable.

Edit: LOL! After reading more posts kuntasensei, I see that the only obsereved differences you take notice of are the loud obvious ones (for audio) such as loud pops or complete loss of picture signal to your TV/Projector (for video). Could it be you are missing some less obvious differences in your observations?

kuntasensei

tonyb wrote: »

"Doing the job", as you so put has different levels of acceptence. Is it not possible 2 cables can both "do the job" yet one does it better than another ? Possibly resulting in differences in sight and sound ?

As I've outlined in detail... NO. TDMS ensures that the only three possible states are PASS, ALMOST PASS, and FAIL.

quadzilla

kuntasensei wrote: »

My point is that in the case of HDMI, even if the cable does a crappy job doing it, it can't introduce the video artifacts we're used to seeing with analog video that people are describing (i.e. an increase in clarity or being more vivid/less dull).

And yet, that's exactly what I saw. Huh... guess there are still some mysteries in the universe after all. If you don't believe me, you're welcome to come by and we'll give 'er a go and see if we can reproduce the effect again. You bring the cheap-o cables.

tonyb

kuntasensei wrote: »

TDMS ensures that the only three possible states are PASS, ALMOST PASS, and FAIL.

LOL....SERIOUSLY ??

OK then, humor me for a moment. Is it not possible 2 cables that both accomplish your criteria of "PASS" can have different qualities about them that result if differences in sight and sound ?

Incidently....thats a yes or no question.

kuntasensei

headrott wrote: »

The old 1's and 0's adage. The only thing is, how much is the 1's and 0's adage based upong real observation (using the senses) instead of electronic equipment? Why is it that some believe that electronic equipment can measure everything there is to measure in the digital realm?

The idea that if the signal gets there it is displayed in the same quality regardless of what metals, dialectrics and construction of the digital cable is hogwash. You are saying that if the signal is high enough quality after transfer through an HDMI cable then it is displayed exactly the same regarless of the cable dialectrics, metal(s), and configuration. I would argue that ALL things affect even a digital signal. Mostly the transfer speed and jitter induction have a large affect on this digital signal, and these are affected by the factors I mentioned above. To say the signal is exactly the same at the end of ALL HDMI cables is preposterous for the reasons I mentioned above. More jitter means lower quality and slower speed means lower quality. I do realise there are minimum speed required and designated by what version of HDMI cable is designated as (1.3c, 1.4a, etc.etc etc), but these are minimum acceptable levels to be designated as an HDMI 1.4a cable etc. If a cable exceed these minimum levels (as I brought up due to reasons above) then why would this cable with higher standards (than the minimum) not have a better picture quality (resolution, color, etc.) than a minimum quality level cable? The same goes for the digital audio signal sent through the HDMI cable.

Edit: LOL! After reading more posts kuntasensei, I see that the only obsereved differences you take notice of are the loud obvious ones (for audio) such as loud pops or complete loss of picture signal to your TV/Projector (for video). Could it be you are missing some less obvious differences in your observations?

I'm pretty sure I've explained this, but here goes. A stronger signal doesn't make those bits of data better. The transmission system used for HDMI is either 100%, borderline failure (sparkles/flashing) or failure. Part of this is because unlike pure digital streaming of binary, TMDS uses a 10-bit block of data to represent larger blocks of data (think the video equivalent of a ZIP file - same result at the end, but if a single byte is corrupted, a large block of data is lost, not just a single bit). As long as the cable meets the BARE MINIMUM THRESHOLD for the picture to be displayed at the sink end, despite factors that might cause intersymbol interference (i.e. RF noise, signal degradation due to cable quality/length, etc.), the data at the other end is identical.

The reason a better cable can't have better picture quality is because we're not talking about analog video, where the information is reconstructed based on signal strength. We're talking DIGITAL. Therefore (and I'm greatly simplifying the process here), if the data stream says "this pixel should be digital 230 in brightness, red 140, blue 120" to create that pixel on the screen, a better signal is not going to make that pixel MORE RED or MORE BLUE or BRIGHTER. It will either display that data... or if there's too much signal loss, it won't display that data (which is essentially what you're seeing when sparkles happen on a borderline cable). Any objective variance from that exact information would be in the display itself, not the cabling. This is why you have to calibrate the black/white levels and color levels of a set. But the DATA ITSELF is the same regardless. It is impossible for there to be a difference, because the data either makes it there or doesn't, regardless of signal strength.

Take note: THE SIGNAL is not the same at the end of all HDMI cables and no one is saying that. What I'm saying is that the signal has no bearing whatsoever on quality in this system, because digital video is based on DATA, not signal strength. All the signal strength in HDMI dictates is whether the data makes it to the sink end or not.

Let me give you an example to try to illustrate how this works electrically (and I'll borrow images from the link posted on page 1 of this thread to illustrate). Keep in mind that I'm simplifying, but you'll get the point.

This is a near-perfect signal. The blue area in the center is basically the threshold for failure. If the waveform intrudes upon that space, the sink end has trouble reading it as either a 1 or a 0. In this case, there is enough space above and below the blue area that the decision at the sink end is easy.

This is a failure state. The waveform has encroached into the failure zone defined by the HDMI spec (which IS a matter of signal strength). At this point, the sink end has to determine whether this is a 1 or a 0 state, but with the high/low signal so close to the failure threshold, it becomes guesswork. Part of the HDMI chipset is decision making where intersymbol interference (ISI) is concerned. Put simply, ISI is where the previous bit of data intrudes upon the following bit. Once the sink end (the display) has to start guessing at this, that's when you start seeing sparkles - the area where the guesswork is happening rarely enough that MOST of the data packets are still intact. However, when the signal is degraded enough for it not be able to guess at enough packets, the signal BLANKS by design.

kuntasensei

tonyb wrote: »

LOL....SERIOUSLY ??

OK then, humor me for a moment. Is it not possible 2 cables that both accomplish your criteria of "PASS" can have different qualities about them that result if differences in sight and sound ?

Incidently....thats a yes or no question.

No, it is not possible. Any differences the cable creates in the data stream would cause failure during error-checking. See my previous post. Put simply, if binary 1 = 1-1.5v and binary 0 = 0-0.6v, a cable sending 1v/0.6v would still send the same 1s and 0s as the perfect cable that sends the full 1.5v/0v. And if that cable's signal degraded to the point that it sent 0.9v/0.7v, it would fail completely because it has reached the point where ISI is too great for the HDMI chipset to determine which are 1s and which are 0s. That's how simple this argument is.

kuntasensei

And yet, that's exactly what I saw. Huh... guess there are still some mysteries in the universe after all. If you don't believe me, you're welcome to come by and we'll give 'er a go and see if we can reproduce the effect again. You bring the cheap-o cables.

quadzilla, I've asked several times in this thread and no one has answered except the OP (who said blurring, I believe). What artifacts did you see that were cleared up by the better cable?

kuntasensei

Also, was this subjective based on viewing material or did you actually examine this phenomenon with test patterns? Did you have to recalibrate your display's contrast, brightness, color or sharpness after changing cables?

headrott

kuntasensei wrote: »

I'm pretty sure I've explained this, but here goes. A stronger signal doesn't make those bits of data better. The transmission system used for HDMI is either 100%, borderline failure (sparkles/flashing) or failure. Part of this is because unlike pure digital streaming of binary, TMDS uses a 10-bit block of data to represent larger blocks of data (think the video equivalent of a ZIP file - same result at the end, but if a single byte is corrupted, a large block of data is lost, not just a single bit). As long as the cable meets the BARE MINIMUM THRESHOLD for the picture to be displayed at the sink end, despite factors that might cause intersymbol interference (i.e. RF noise, signal degradation due to cable quality/length, etc.), the data at the other end is identical.

The reason a better cable can't have better picture quality is because we're not talking about analog video, where the information is reconstructed based on signal strength. We're talking DIGITAL. Therefore (and I'm greatly simplifying the process here), if the data stream says "this pixel should be digital 230 in brightness, red 140, blue 120" to create that pixel on the screen, a better signal is not going to make that pixel MORE RED or MORE BLUE or BRIGHTER. It will either display that data... or if there's too much signal loss, it won't display that data (which is essentially what you're seeing when sparkles happen on a borderline cable). Any objective variance from that exact information would be in the display itself, not the cabling. This is why you have to calibrate the black/white levels and color levels of a set. But the DATA ITSELF is the same regardless. It is impossible for there to be a difference, because the data either makes it there or doesn't, regardless of signal strength.

Take note: THE SIGNAL is not the same at the end of all HDMI cables and no one is saying that. What I'm saying is that the signal has no bearing whatsoever on quality in this system, because digital video is based on DATA, not signal strength. All the signal strength in HDMI dictates is whether the data makes it to the sink end or not.

Let me give you an example to try to illustrate how this works electrically (and I'll borrow images from the link posted on page 1 of this thread to illustrate). Keep in mind that I'm simplifying, but you'll get the point.

This is a near-perfect signal. The blue area in the center is basically the threshold for failure. If the waveform intrudes upon that space, the sink end has trouble reading it as either a 1 or a 0. In this case, there is enough space above and below the blue area that the decision at the sink end is easy.

This is a failure state. The waveform has encroached into the failure zone defined by the HDMI spec (which IS a matter of signal strength). At this point, the sink end has to determine whether this is a 1 or a 0 state, but with the high/low signal so close to the failure threshold, it becomes guesswork. Part of the HDMI chipset is decision making where intersymbol interference (ISI) is concerned. Put simply, ISI is where the previous bit of data intrudes upon the following bit. Once the sink end (the display) has to start guessing at this, that's when you start seeing sparkles - the area where the guesswork is happening rarely enough that MOST of the data packets are still intact. However, when the signal is degraded enough for it not be able to guess at enough packets, the signal BLANKS by design.

You addressed only part of what I brought up in my post. It seems the responses to the questions I (and others) ask are rehearsed responses as they all sound the same. I do not believe that you are really reading what I said and contemplating it, and then responding to it without using what has been said on another web site. There is no independent thought it seems when it comes to digital cables and quality of picture and audio. (ironically, it seems you are part of the Borg or something). It's all been said before and will keep being said regardless if it is reality (or at least with disreagrd to the fact that what you "Borgites" say may not be full reality).

I'm pretty sure you and many others have explained what was posted above and , but it still didn't address what I brought up. I agree that the digital signal in the HDMI cable is based upon data, just as every other digital cable is. But, to say that DATA is not affected by signal strength is hogwash. That goes for HDMI, S/PDIF, Toslink, and any other digital (DATA based) signal. What causes the data to fail and/or become corrupted? One of the reasons is signal streangth (jitter). More jitter can be introduced to the data when the signal is transmitted at a slower rate (the two things I brought up in my previous post). Jitter is the amount of error in the digital signal and speed is the rate the data travels. If you get the data from the source to the audio/video converting device quicker, you get less jitter introduced (and there are many other reasons for introduction of jitter as well) and you get a more asily converted digital to analog signal on the receiving end. If the converting piece of equipment can convert the digital signal to analog in a more efficient manner due to less jitter (data error) and receiving it faster and more efficiently, then you get a better picture/sound quality. That's a pretty simple concept to understand, right?

I will quote the first and last portions of my last post (only one of the parts you didn't respond to) as well. Perhaps this time you will consider reading, thinking and responding the these ideas? Thanks again:

headrott wrote: »

The old 1's and 0's adage. The only thing is, how much is the 1's and 0's adage based upong real observation (using the senses) instead of electronic equipment? Why is it that some believe that electronic equipment can measure everything there is to measure in the digital realm?

Edit: LOL! After reading more posts kuntasensei, I see that the only obsereved differences you take notice of are the loud obvious ones (for audio) such as loud pops or complete loss of picture signal to your TV/Projector (for video). Could it be you are missing some less obvious differences in your observations?

tonyb

kuntasensei wrote: »

That's how simple this argument is.

LOL.....if it was as simple as you make it out to be, then lots of cable makers would be out of buisness. Also, for them to actually stay in buisness, you have to put forth products that people could visually see or hear differences in, otherwise nobody would buy them. This brings us to what cables have YOU personally tried to validate this judgement ?

CarlosD

I'm surprised no one has asked in this two-page thread whether the two cables used by the OP were same-generation. If the cheap cable was generation 1.0, 1.1 or 1.2 -- which wouldn't be surprising in that store -- and the other cable was 1.3 or better, then yeah, you're going to see a difference.

sodablue

If there's a difference, you can measure it.

headrott

sodablue wrote: »

If there's a difference, you can measure it.

So, what meter are you using to measure imaging and soundstage width and depth? Or, are you referring to measuring these with your ears, brain and consciousness?

BlueFox

sodablue wrote: »

If there's a difference, you can measure it.

Assuming you know what to measure. However, there is still a lot to be discovered. For example, how do you measure changes that happen at the atomic level? Obviously, they occur, and have audible effects. Other than some basic concepts such as currrent, voltage, etc. we have only scratched the surface of what is occuring at the atomic level. As we get a better understanding of quantom physics then we will have additional measurements to help quantify the differences people hear, and in this case, see.

So, the end result is cables matter. Some work better than others.

tonyb

sodablue wrote: »

If there's a difference, you can measure it.

Your not the first to propose that thought and certainly won't be the last. Kindly inform us what tool is used to measure sounstage width, height, depth, tone, so we can all measure for ourselves.

I would imagine any tool you come up with is a digital device. Problem comes in at we hear in analog, not 1's or 0's, and we all hear differently.

Jhayman

Not really because there are always people willing to part with their money reguardless of what someone tells them..
where do you think snakeoil comes from..
But hey if you see a difference then you see a difference..

tonyb wrote: »

LOL.....if it was as simple as you make it out to be, then lots of cable makers would be out of buisness. Also, for them to actually stay in buisness, you have to put forth products that people could visually see or hear differences in, otherwise nobody would buy them. This brings us to what cables have YOU personally tried to validate this judgement ?

kuntasensei

headrott wrote: »

I'm pretty sure you and many others have explained what was posted above and , but it still didn't address what I brought up.

Pretty sure that I did address what you brought up, but I will break up this response so it's clear.

headrott wrote: »

I agree that the digital signal in the HDMI cable is based upon data, just as every other digital cable is. But, to say that DATA is not affected by signal strength is hogwash. That goes for HDMI, S/PDIF, Toslink, and any other digital (DATA based) signal.

I didn't say that data is not affected by signal strength. It clearly is, which is why you have the error correction and redundancy (2 data leads, phase reversed) in HDMI cables (which is what differentiates it from S/PDIF and TOSlink).

headrott wrote: »

What causes the data to fail and/or become corrupted? One of the reasons is signal streangth (jitter). More jitter can be introduced to the data when the signal is transmitted at a slower rate (the two things I brought up in my previous post). Jitter is the amount of error in the digital signal and speed is the rate the data travels. If you get the data from the source to the audio/video converting device quicker, you get less jitter introduced (and there are many other reasons for introduction of jitter as well) and you get a more asily converted digital to analog signal on the receiving end. If the converting piece of equipment can convert the digital signal to analog in a more efficient manner due to less jitter (data error) and receiving it faster and more efficiently, then you get a better picture/sound quality. That's a pretty simple concept to understand, right?

No, this is what you have wrong with what we're discussing. You aren't sending video or audio over HDMI - you're sending packets of data. In this case, 10b encoded packets. So long as these packets arrive intact, the end result is the same - your display decodes each packet into the per-pixel data and sends it to the display circuitry to undergo the display's controls (color, brightness, contrast, sharpness) before being converted to RGB (if not already sent as RGB) for display to the panel. If one of these packets DOES NOT arrive intact, the system doesn't have any data to send to the display. It can't send PARTIAL data if the entire packet is corrupted. As I mentioned before, the only exception is borderline signal, in which case the ISI correction tries to predictively fill in the gaps, resulting in sparkling pixels where the per-pixel data is lost. This can not affect "picture quality" (i.e. brightness, sharpness, contrast, color, tint) one bit. It either works, almost works, or doesn't work at all.

It would be like if I tried to send you a text file of Moby Dick. With a system with no error correction/checking, if there was an error in transmission, you might have perfectly normal text up until the point that data was lost, at which point you would have gibberish. With error correction (as hard drives implement), the data packets are retried if the checksum (the error checking bits) are incorrect, which indicates corruption. This is how a file can be copied to a hard drive without corruption, despite any RF interference or borderline signal. If, however, the cable to your hard drive is flawed in some way, it simply can't copy the file. Much in the same way, you either get ALL THE DATA or NONE OF IT, except that HDMI has predictive correction for borderline interference to try to recover corrupted data to prevent a catastrophic failure that would blank the image entirely.

A similar process occurs with the audio codecs carried over HDMI (except, as explained before, in the case of PCM). The error check is built into the codec. Once the data is transferred to your AVR over HDMI, it checks each packet of data to make sure it matches the data originally sent. If it does NOT due to signal issues, it simply doesn't send that block of data to your receiver's DAC... because the result of a corrupted packet of data would be a loud burst of noise. This was an issue with S/PDIF and some DVD players where CDs encoded with DTS would try to send as PCM instead, and with no error checking, the result was white noise. This lack of error checking is also why when there was a signal issue, there would be a resulting crackle or momentary noise burst before it could recover the bitstream. That isn't the case with HDMI, for reasons already stated.

headrott wrote: »

I will quote the first and last portions of my last post (only one of the parts you didn't respond to) as well. Perhaps this time you will consider reading, thinking and responding the these ideas? Thanks again:

If there's anything I missed, please let me know.

kuntasensei

tonyb wrote: »

LOL.....if it was as simple as you make it out to be, then lots of cable makers would be out of buisness. Also, for them to actually stay in buisness, you have to put forth products that people could visually see or hear differences in, otherwise nobody would buy them. This brings us to what cables have YOU personally tried to validate this judgement ?

If you're referring to analog cables (ICs, speaker cables, etc.) then there are differences. That's because that information is relayed based on the signal levels in the cable, so you want the most unadulterated version of the original to reach the endpoint.

In the case of digital transfer systems with error-correction, I don't need to test what science says is impossible and what the makers of the interface state is impossible, any more than I need to swap hard drive cables because I think one will somehow transmit the data better. Either it transmits the data uncorrupted or it doesn't. Just like a hard drive's SATA or IDE interfaces, HDMI has error correction to ensure that the bits that are sent at the beginning of the chain are the same bits received at the end.

What you guys are claiming is possible is like claiming that if I copy a text file of Moby Dick from one hard drive to another using a certain cable, it will improve the words in the book. You would agree that's nonsense, right? Because digital transmission of data in your computer is designed such that when it sends a text file of Moby Dick across the interface, it checks for errors at the other end of the interface to make sure the data arrived intact... and if it doesn't arrive intact, it retries the failed packet of data or gives you an error message that the file can't be copied. HDMI is no different. The bits at one end will be the bits at the other... and if not, you get failure (in the form of no picture or no audio). That's just scientific fact. And not a single person here has offered a logical explanation countering what I've explained thus far, or offered a possible reason that one cable could have an objectively "better" picture if both cables are passing identical digital data.

kuntasensei

BlueFox wrote: »

Assuming you know what to measure. However, there is still a lot to be discovered. For example, how do you measure changes that happen at the atomic level? Obviously, they occur, and have audible effects. Other than some basic concepts such as currrent, voltage, etc. we have only scratched the surface of what is occuring at the atomic level. As we get a better understanding of quantom physics then we will have additional measurements to help quantify the differences people hear, and in this case, see.

So, the end result is cables matter. Some work better than others.

In the case of analog cables, I agree that you can hear an audible difference based on any number of factors. And I'm definitely not disagreeing that cables matter or that some work better than others. Nor am I saying that a high-grade HDMI cable can't have a higher signal level at the endpoint than a cheaper HDMI cable. I hope I've been clear on that.

I'm just saying that in the case of HDMI and digital transmission methods, the bits must be the same at the end as they are at the beginning or the transmission fails altogether. And by design, if the cable fails at transmitting this data error-free, this can't be perceived as a change in the audio or video - the audio or video simply doesn't play, because (on the audio side, at least) the DAC has no data to convert to analog and (on the video side) the decoding is thrown off such that no picture can be displayed.

headrott

kuntasensei wrote: »

Pretty sure that I did address what you brought up, but I will break up this response so it's clear.

kuntasensei wrote: »

I didn't say that data is not affected by signal strength. It clearly is, which is why you have the error correction and redundancy (2 data leads, phase reversed) in HDMI cables (which is what differentiates it from S/PDIF and TOSlink).

kuntasensei wrote: »

No, this is what you have wrong with what we're discussing. You aren't sending video or audio over HDMI - you're sending packets of data. In this case, 10b encoded packets. So long as these packets arrive intact, the end result is the same - your display decodes each packet into the per-pixel data and sends it to the display circuitry to undergo the display's controls (color, brightness, contrast, sharpness) before being converted to RGB (if not already sent as RGB) for display to the panel. If one of these packets DOES NOT arrive intact, the system doesn't have any data to send to the display. It can't send PARTIAL data if the entire packet is corrupted. As I mentioned before, the only exception is borderline signal, in which case the ISI correction tries to predictively fill in the gaps, resulting in sparkling pixels where the per-pixel data is lost. This can not affect "picture quality" (i.e. brightness, sharpness, contrast, color, tint) one bit. It either works, almost works, or doesn't work at all.

It would be like if I tried to send you a text file of Moby Dick. With a system with no error correction/checking, if there was an error in transmission, you might have perfectly normal text up until the point that data was lost, at which point you would have gibberish. With error correction (as hard drives implement), the data packets are retried if the checksum (the error checking bits) are incorrect, which indicates corruption. This is how a file can be copied to a hard drive without corruption, despite any RF interference or borderline signal. If, however, the cable to your hard drive is flawed in some way, it simply can't copy the file. Much in the same way, you either get ALL THE DATA or NONE OF IT, except that HDMI has predictive correction for borderline interference to try to recover corrupted data to prevent a catastrophic failure that would blank the image entirely.

A similar process occurs with the audio codecs carried over HDMI (except, as explained before, in the case of PCM). The error check is built into the codec. Once the data is transferred to your AVR over HDMI, it checks each packet of data to make sure it matches the data originally sent. If it does NOT due to signal issues, it simply doesn't send that block of data to your receiver's DAC... because the result of a corrupted packet of data would be a loud burst of noise. This was an issue with S/PDIF and some DVD players where CDs encoded with DTS would try to send as PCM instead, and with no error checking, the result was white noise. This lack of error checking is also why when there was a signal issue, there would be a resulting crackle or momentary noise burst before it could recover the bitstream. That isn't the case with HDMI, for reasons already stated.


If there's anything I missed, please let me know.

I will start with the last part of my quote this time so it's fresh in your mind this time. Can you respond to this please?:

headrott wrote: »

I will quote the first and last portions of my last post (only one of the parts you didn't respond to) as well. Perhaps this time you will consider reading, thinking and responding the these ideas? Thanks again:

:

headrott wrote: »

The old 1's and 0's adage. The only thing is, how much is the 1's and 0's adage based upong real observation (using the senses) instead of electronic equipment? Why is it that some believe that electronic equipment can measure everything there is to measure in the digital realm?

Edit: LOL! After reading more posts kuntasensei, I see that the only obsereved differences you take notice of are the loud obvious ones (for audio) such as loud pops or complete loss of picture signal to your TV/Projector (for video). Could it be you are missing some less obvious differences in your observations?

Also, you did respond at all to the fact that data transmission speed will affect the conversion of the data (1's and 0's, NOT video and/or audio) from these 1's and 0's back into audio and video. And, this transmission speed is based upon the data error correction rate. Why is it that you think that all data error correction in all these dual leads (phased reversed) in all HDMI cables are equivalent? The leads are made out of metal? As some have brought up, some are steel cables, some are copper, some are very very pure copper, and some are silver. Some may also be a combination of silver and copper. Why do you think that the out of phase signal and the "true" signal will travel down these HDMI wires exactly the same regardless of what metals, dialectrics, and cable configuration are used? This is what determines the accuracy of the data recieved by the TV/projector, etc. And, the metal purity and type, dialectric, and configuration will also determine the speed the signal travels down the cable. The faster and more consistant the signal travels, the more efficiently the recieving equipment can convert the data (1's and 0's, NOT audio/video) back into the picture you see and audio you hear. The more efficiently it's converted, the better quality audio/video you will see/hear. YES, the better resolution you will see. No really.

I hope the above is clear as I am doing about 10 things at once.

kuntasensei

Sorry... It isn't including quoted items when I quote you, so I'll cut-and-paste.

headrott wrote: »

The old 1's and 0's adage. The only thing is, how much is the 1's and 0's adage based upong real observation (using the senses) instead of electronic equipment? Why is it that some believe that electronic equipment can measure everything there is to measure in the digital realm?

By the time you can observe it, the data isn't the question... it's the conversion of the data back into a picture or sound, at which point that conversion is the issue, not the transmission of the data. The data itself is a known quantity that will be the same at the beginning and end. What the display or DAC does with it at the end is what you observe. That has nothing to do with measuring anything electronically.

headrott wrote: »

Edit: LOL! After reading more posts kuntasensei, I see that the only obsereved differences you take notice of are the loud obvious ones (for audio) such as loud pops or complete loss of picture signal to your TV/Projector (for video). Could it be you are missing some less obvious differences in your observations?

The loud obvious ones (pops) that you're referring to were in reference to issues with S/PDIF, not HDMI. They aren't relevant to this discussion because HDMI has error checking that S/PDIF did not. As far as complete loss of picture signal to MY display, that's not at issue... HDMI LLC are the ones who say that this will occur with data loss, not me. What I observed with my display personally was sparkles (i.e. pixels not resolving) caused by me using an in-line repeater because I believed I needed one when I first installed my cabling because of the length of the run to my projector. Once the repeater was out of the chain, the picture resolved fully with no loss of pixel data. If you're asking me how I observed that to be true, I used Spears & Munsil's high frequency resolution chart and chroma/luma resolution patterns. I also used the free-to-download AVS 709 HD test disc's 1080p patterns, which have single-pixel checkerboard patterns and a vast array of test patterns for ensuring that the display is correctly resolving the information in the bitstream. For sake of consistency, I also used an EyeOne Display LT to ensure that my projector's grayscale was to spec and the color gamut was as close to the defined standard as possible.

headrott wrote: »

Also, you did respond at all to the fact that data transmission speed will affect the conversion of the data (1's and 0's, NOT video and/or audio) from these 1's and 0's back into audio and video. And, this transmission speed is based upon the data error correction rate. Why is it that you think that all data error correction in all these dual leads (phased reversed) in all HDMI cables are equivalent?

The data error correction isn't a function of the cabling - it's a function of the HDMI interface (the chipset at either end of the chain). Data transmission speed (bandwidth) affects the transmission in that a faulty cable may perfectly resolve a 720p signal (lower bandwidth) but not resolve a 1080p signal at all (due to the increase in bandwidth). But if two cables both resolve a 1080p signal at the endpoint, it doesn't matter which does it with a higher signal strength, because the display itself doesn't see that. All it sees are 1s and 0s.

headrott wrote: »

The leads are made out of metal? As some have brought up, some are steel cables, some are copper, some are very very pure copper, and some are silver. Some may also be a combination of silver and copper. Why do you think that the out of phase signal and the "true" signal will travel down these HDMI wires exactly the same regardless of what metals, dialectrics, and cable configuration are used? This is what determines the accuracy of the data recieved by the TV/projector, etc. And, the metal purity and type, dialectric, and configuration will also determine the speed the signal travels down the cable. The faster and more consistant the signal travels, the more efficiently the recieving equipment can convert the data (1's and 0's, NOT audio/video) back into the picture you see and audio you hear.

I guess you're not getting what I'm saying. I'm not arguing that one cable may transfer the data with less errors than another cable. That goes without saying. What I'm saying is that at the endpoint of the chain (the sink/display end of an HDMI interface), all it sees are 1s or 0s, pass or fail. If the cheap cable is good enough to get this data to the sink end, then the more expensive cable can not magically improve this data when it sends it. They both send the same data.

To steal an analogy from one of Audioquest's white papers, you have two students... A grade of 60 is failing. One student gets a 95, the other gets a 65, but the report cards just say PASS or FAIL. Both of these students passed. I'm not arguing that the student who got a 95 didn't do a better job of passing than the dumbass who made a 65... I'm saying that the parent who sees the report card (display) only sees PASS or FAIL... and even the cable that made a 65 is still seen as a 100% pass.

headrott wrote: »

The more efficiently it's converted, the better quality audio/video you will see/hear. YES, the better resolution you will see. No really.

Actually, NO. Not really. Because beyond a point that error correction says there are too many errors, what you will see/hear is NOTHING. You don't lose resolution when those errors occur... You simply don't get a picture. Your student has failed.

I really hope I'm making sense... 'cause I'm about to drop all this crap and go watch the Blu-ray of Star Trek. :cheesygrin: