8 ms·

My patience for the line, "It is digital. It either works or it doesn't" ended a long time ago. "Digital" signals are analog signals, but the only difference i

by micks56 17y ago

My patience for the line, "It is digital. It either works or it doesn't" ended a long time ago. "Digital" signals are analog signals, but the only difference is that they are restricted to being above or below some threshold. But around that threshold there is a gray area where you can't really tell whether your signal will be interpreted as 1 or 0. I am not defending the need for high-end HDMI cables. But saying "It's digital so don't worry" is wrong. There are reasons that "digital" cables use twisted pair. Wow, even some "digital" cable standards specify the number of twists per inch required for reliable operation. And wow, some cable standards even specify shielded cable is required. I wonder why. Here is a fun exercise for those that think "digital" signals don't need engineering steps to protect signal integrity: build all of your cables (or PCBs for that matter) with straight signals and you will have an excellent time trying to debug why your communications don't work. Bonus fun for making the cable length 1/4 of your signal wavelength.

matwood 17y ago
I think the point of the "either works or it doesn't" is a comparison versus analog. With an analog signal you could get slightly better results by getting better cables (or worse with worse cables). If you have a poor digital cable it flat out doesn't work. If the cable you're using works, buying a more expensive cable isn't going to make it work any better. Either the 1s and 0s made it from the source to the destination or they didn't. No one is claiming that there isn't engineering that needs to happen to make a digital signal reliably travel from the source to the receiver.
- micks56 17y ago
  I think your understanding of cables is off. All signals are analog. Every single one. (Actually, I take that back. With the exception of quantum computers, to date, all signals are analog). A "digital" cable doesn't just work or not work. It is possible to receive spurious bit errors for many reasons. For example, you turn up the volume to your awesome surround sound speakers, which causes more current to flow through your speaker wires that happen to be running parallel to your horrible HDMI cable. The increased current causes interference in your low-power HDMI cable, causing bit errors in the transmission.
  - deleted 17y ago
    [deleted]
  - axod 17y ago
    >> "It is possible to receive spurious bit errors for many reasons." Surely that's why there's error correction layered on top? Instead of arguing about what might happen, why not find an HDMI device that'll show you how many unrecoverable bit errors it has detected in the stream... Can't be that hard to do. If my hard disk can send data over a tiny crappy unshielded cheap USB cable without a single bit error, I'd be willing to bet money that an HDMI cable isn't that much different.
    - tedunangst 17y ago
      HDMI doesn't do error correction for video.
  - steveklabnik 17y ago
    Isn't HDMI supposed to do error correction on both sides, though? I could be totally making that up, I thought I remember hearing that a while back.
  - Tichy 17y ago
    There is this weird thing called error detection/correction.
    - tedunangst 17y ago
      which HDMI doesn't do.
      - Tichy 17y ago
        Hm, no idea, but I find that very hard to believe. I suspect digital transmission of information is almost impossible without error correction. IANAEE, though (I am not an electronics engineer).
        17y ago
- wwalker3 17y ago
  That's still not correct. For HDMI in particular, there's no error correction at all on the video data (though there is on the audio and control data). So if one bit gets flipped in the video data as it goes through the cable, you're going to see that wrong bit on screen. You'd have to have an insanely high bit error rate for your eyes to notice it, but it's there, and it gradually gets worse as the error rate increases. What could flip a bit in a cable? Any number of things. EM interference from outside a badly shielded cable. EM crosstalk between conductors inside a badly designed cable. Signal reflections at badly designed connectors. Basically anything that can happen to any other cable, whether the signal that goes over it is considered to be analog or digital. I assume the reason HDMI applies EC to the audio and control data is that errors in those channels are more noticeable to the user, whereas errors at reasonable rates in the video will mostly sneak by. The HDMI spec at http://www.hdmi.org/download/HDMI_Spec_1.3_GM1.pdf http://www.hdmi.org/download/HDMI_Spec_1.3_GM1.pdf is a great source of information about this.
  - ErrantX 17y ago
    Indeed. However it uses TMDS [1] which is a "blind mans" error reduction technique. 1. http://en.wikipedia.org/wiki/Transition_Minimized_Differential_Signaling http://en.wikipedia.org/wiki/Transition_Minimized_Differenti...
    - wwalker3 17y ago
      Totally true. HDMI takes many steps to try to reduce errors to a reasonable rate. In practice, this rate is usually low enough to ignore, even with cheap cables. I was just making the point that there is indeed a progressive degradation in image quality with increasing error rate, even in HDMI.
  - jcromartie 17y ago
    I've had this happen. You see what are called "sparkles" when you get a lot of failures (and it truly looks like sparkling glitter on your TV). It turned out to be the TV's connector more than the cable itself. The same $4 cable worked fine on a replacement set.
  - 17y ago
- ghshephard 17y ago
  Clearly you've never had an Ethernet Cable that got caught in a door. Or was terminated poorly. Or doesn't have the insulator sheath under the crimp. Or run parallel to a set of Florescent light ballasts. All of these events can reduce performance on Ethernet without causing it to fail outright. There is a reason why every single TIA/EIA 568 cable plant is carefully tested for things like Near End Cross Talk (NEXT), Latency, Skew, etc.. There is also a reason why there is an entire _discipline_ dedicated to ensuring that the "Digital" signal not only has a channel, but a meticulously crafted one. (See: http://www.linktionary.com/t/tia_cabling.html http://www.linktionary.com/t/tia_cabling.html for details) To reiterates the OP - there is no "Digital Signal" - signals are analog in nature, and they need an analog channel to transmit them. That analog channel needs to be engineered carefully to get the lowest EBR (Error Bit Rate) possible. What's interesting is the Failure case of the Digital CODEC on the other end - some may reduce transmit rate in the presence of an increased EBR resulting from dropped packets. Or some may seize up and cease to function. In the degraded case, having a pristine analog channel from the transmitter to the receiver will certainly result in a better digital signal. There is also the issue of future proofing - We're installing an entire plant of Category 6a cable right now in one of our data centers for a gigabit environment - Category 6a is like the "Monster" version of Category 5e/6 - It seems like a douchey way to do a network install, except when you consider the following - (1) this cable plant will be in use for 10-15 years, (2) We're testing a bunch of Nexus 5010s that will likely make good use of that 6a for 10 Gigabit. So, in addition to passing _today's_ signal flawlessly, it will also pass tomorrow's. This might be an important factor if your HDMI cable is being run through hard to access cabinets/walls. Now, with all that said, it is still probably the case that the $150 Monster Cables (under normal circumstances) don't have a lower EBR than a $10 cable, but, in the face of RF interference, It may actually be a better performer. I don't know, but I wouldn't discard the possibility without a bit of research and education.
  - lkjhgvbnm 17y ago
    But did you use audiophile, linear crystal aligned cables? And did you install them the correct way round? https://usa.denon.com/ProductDetails/3429.asp https://usa.denon.com/ProductDetails/3429.asp Presumably on ethernet you have to decide if you want the Tx or Rx signal to have the extra digital nuance?
- ghshephard 17y ago
  Note, it's traditional on HN to add the phrase [EDIT] when making substantive modifications to comments, particularly if someone has already responded to your original comment.
  - pbhjpbhj 17y ago
    OT: The site should really help to enforce such niceties. When you edit you should get a "reason for editing" box.
mrcharles 17y ago
The point is not that you can use anything, the point is that you only need a certain level, and then it's good enough. All my HDMI cables are from monoprice.com, I don't think I paid more than $4 for a single cable, and I can't imagine what kind of EM interference I'd need to mess with them. I have so many electronics in my house I'm probably on a watch list.
deleted 17y ago
[deleted]
- micks56 17y ago
  Are the colors 0026FF and 8026FF the same? No, they are not. And the difference between blue (0026FF) and purple (8026FF) is a 1 bit error. You will see an image, but not the image your DVD told your TV to display. edit: This comment makes a lot less sense with the deleted comment removed.
  - ramchip 17y ago
    It takes a lot of noise to alter the digital signal like this. If we're talking long distance, like a telephone line, the signal gets weak enough that it can happen regularly, but on the cable from the DVD to the TV the voltage drop is ridiculously low. Noise doesn't affect your signal by 4 volts unless you have a serious problem with your system.
    - micks56 17y ago
      Actually, I think that it takes the exact same amount of noise to flip a bit as it does to transmit a bit. Through the principle of superposition, if you transmit a 0 with X watts, and I transmit a 1 with X watts, our combined signal will be somewhere in the middle, which can cause a bit flip. I am not talking about voltage drop from end to end, which is a separate issue. I am talking about interference occurring adjacent to any point on the cable that you pick.
mseebach 17y ago
I think "It is digital. It either works or it doesn't" in the context of A/V refers to the quality of the converted analog signal - what comes out of the speakers or is visible on the screen. And the signal getting through can either work or not, no matter how well engineered the cable is, isn't that correct?
- micks56 17y ago
  But the reason why your digital TV shows the correct screen is because the cable transmitted the "digital" bits between your DVD player and the TV correctly. If you have a poorly made cable you will get bit errors. Electromagnetic interference from other A/V equipment could also cause bit errors. A well made cable with twisted pairs, proper shielding (few people do this correctly), and well formed connector crimps will prevent those bit errors. With bit errors, what your awesome Blu-Ray player decodes off of the Blue-Ray disc will not be what is shown on the screen (assuming there isn't bit error correction in the TV, etc.). And your speakers are playing an analog signal. Cable quality matters even more there.
  - mseebach 17y ago
    > But the reason why your digital TV shows the correct screen is because the cable transmitted the "digital" bits between your DVD player and the TV correctly. If you have a poorly made cable you will get bit errors. Yes. Which is why the poorly made cable can be said to not work. > And your speakers are playing an analog signal. Huh? I've never heard of HDMI cables capable of carrying analog sound.
  - oostevo 17y ago
    Yup, the correct signal might not get through if you don't have perfect shielding. And a speck of dust on a CD could theoretically ruin a whole song. That's why CDs (and cellphones, modems, and countless other digital devices) use channel encoding.[1] That way you don't have to have a perfectly noise-free signal to reconstruct the original information. I don't know that many specifics of the DVD or Blu-Ray standards, but I'd put money on them using Reed-Solomon or something similar. [1] http://en.wikipedia.org/wiki/Reed-Solomon_error_correction#Data_storage http://en.wikipedia.org/wiki/Reed-Solomon_error_correction#D... (Edit: forgot footnote)
GrandMasterBirt 17y ago
Ok when it comes to HDMI the goal was to always have good quality. The difference between an analog and digital is that digital ENCODES the information, it either gets there or not. The only thing the cable gives you is bandwidth. Analog is different. The signal is itself the image, so a poor signal = poor image. MAYBE if you have a projector projecting onto a movie theater screen will a better HDMI cable matter... maybe? because of bandwidth limitations if the sender is smart enough it might send info at a lower resolution. Other than that I can't see theoretically why a good HDMI cable will help. Also on my 42'' tv, I've yet to be shown a performance improvement when connecting my XBOX 360 via component or hdmi. It looks identical. And if HDMI is better than component, then I don't see a reason why you would ever need a good HDMI cable unless you are a movie theater and the theoretical problem does exist. Edit regarding bit errors... Lets assume that the cable you bought is a good quality cable. By good quality I mean most seem to be shielded and not cut and no shorts. This is a reasonable expectation. I've yet to see an argument for buying more expensive super gold plated uber network cables. Hey why is your network cable that handles SO MUCH DATA not gold plated shielded etc.?
- micks56 17y ago
  My network cable that handles all my data doesn't have gold plating or shielding because the cable as designed is sufficient to operate at Ethernet speeds, temperatures, humidity, etc. If you want to operate a faster network, or one in a harsh environment, you will be using shielded cables with gold plates and more twists per inch.
deleted 17y ago
[deleted]
lurkinggrue 17y ago
The real time to worry about the quality of those cables is when you go over 6 feet.
- frou_dh 17y ago
  Unless you are making your own cables, I don't see why. If the >6 feet cheap cable you bought doesn't work properly then it is faulty and you can get a refund.
  - derefr 17y ago
    "The real time to worry about the quality of those cables is when you go over 6 feet," would make sense as something said to the cable manufacturer. Translated to consumer-speak, that would be "it's really quite hard to find cheap HDMI cables longer than 6 feet from a well-known brand." (Of course, shady brands will just sell the crappy cables and rely on people's innate laziness and stores with no-refunds policies.)
- __david__ 17y ago
  Not really, I have 2 $12 25 foot hdmi cable that work just great. I bought the cheapest one I could find because, hey, if it doesn't work I'm only out $12. But it's been working great for a couple years now.
ugh 17y ago
I guess the argument should have been that once you cross a certain threshold, cable quality doesn’t matter. That was of course also true for analog signals (human senses are only so good), but the transition from good signal to bad signal might have different characteristics with digital signals. While a image from a analog signal will only get noisier and noisier as signal quality decreases, images from a digital signal will first show artifacts and then just stop displaying altogether. That’s a rather sudden transition. One second the signal is there, the other it's gone. Something like that just doesn’t happen with analog signals. (I’m basing this on my experience with terrestrial digital broadcasting – could be totally wrong for HDMI connection but I doubt it.) I would guess that how sudden that transition is has something to do with the error correction and the codec of the signal. How many wrong bits can the error correction reconstruct? And, as soon as the wrong bits get past the error correction, how many wrong bits can the decoder handle and still reconstruct a image (albeit one with artifacts)? It would certainly be interesting to know how that problem was solved for HDMI connections. If you know the maximum bit error rates for your cables figuring out which are the right ones should be easy, given enough testing :)
lmkg 17y ago
There is still a qualitative difference between digital and analog signals. With analog signals, you can always get higher fidelity by upgrading components (until something else becomes the bottleneck). With digital, there are gradients of "wrong" but there is only one "right." Once you hit the threshold of bits not being flipped, getting more expensive and higher-quality components will not get you better-sounding playback. A digital cable can achieve literally perfect playback. Analog cannot reach perfection, which means it's always possible to improve. I'm not an electrical engineer so I don't know what the threshold of perfection is, but if the consumer reports can't tell the fancy cable apart from the Radio Shack equivalent of two-buck chuck, I'm not going to worry about it. On an unrelated note: this is a listing on amazon for 6 feet of digital audio cable for over a thousand dollars. Read the comments. Comic gold. http://www.amazon.com/Denon-AKDL1-Dedicated-Link-Cable/dp/B000I1X6PM http://www.amazon.com/Denon-AKDL1-Dedicated-Link-Cable/dp/B0...
blackguardx 17y ago
If a cable has an HDMI logo on the box, it is guaranteed to work. Specs are specs.
lkjhgvbnm 17y ago
>"Digital" signals are analog signals True that's why I reject TVs with a video chipset, I want a TV and a DVD player that uses valves for the video processing. I wonder how big an MPEG-2 decoder in valves would be?

by micks56 17y ago

matwood 17y ago

I think the point of the "either works or it doesn't" is a comparison versus analog. With an analog signal you could get slightly better results by getting better cables (or worse with worse cables). If you have a poor digital cable it flat out doesn't work. If the cable you're using works, buying a more expensive cable isn't going to make it work any better. Either the 1s and 0s made it from the source to the destination or they didn't. No one is claiming that there isn't engineering that needs to happen to make a digital signal reliably travel from the source to the receiver.

micks56 17y ago
I think your understanding of cables is off. All signals are analog. Every single one. (Actually, I take that back. With the exception of quantum computers, to date, all signals are analog). A "digital" cable doesn't just work or not work. It is possible to receive spurious bit errors for many reasons. For example, you turn up the volume to your awesome surround sound speakers, which causes more current to flow through your speaker wires that happen to be running parallel to your horrible HDMI cable. The increased current causes interference in your low-power HDMI cable, causing bit errors in the transmission.
- deleted 17y ago
  [deleted]
- axod 17y ago
  >> "It is possible to receive spurious bit errors for many reasons." Surely that's why there's error correction layered on top? Instead of arguing about what might happen, why not find an HDMI device that'll show you how many unrecoverable bit errors it has detected in the stream... Can't be that hard to do. If my hard disk can send data over a tiny crappy unshielded cheap USB cable without a single bit error, I'd be willing to bet money that an HDMI cable isn't that much different.
  - tedunangst 17y ago
    HDMI doesn't do error correction for video.
- steveklabnik 17y ago
  Isn't HDMI supposed to do error correction on both sides, though? I could be totally making that up, I thought I remember hearing that a while back.
- Tichy 17y ago
  There is this weird thing called error detection/correction.
  - tedunangst 17y ago
    which HDMI doesn't do.
    - Tichy 17y ago
      Hm, no idea, but I find that very hard to believe. I suspect digital transmission of information is almost impossible without error correction. IANAEE, though (I am not an electronics engineer).
      - 17y ago
wwalker3 17y ago
That's still not correct. For HDMI in particular, there's no error correction at all on the video data (though there is on the audio and control data). So if one bit gets flipped in the video data as it goes through the cable, you're going to see that wrong bit on screen. You'd have to have an insanely high bit error rate for your eyes to notice it, but it's there, and it gradually gets worse as the error rate increases. What could flip a bit in a cable? Any number of things. EM interference from outside a badly shielded cable. EM crosstalk between conductors inside a badly designed cable. Signal reflections at badly designed connectors. Basically anything that can happen to any other cable, whether the signal that goes over it is considered to be analog or digital. I assume the reason HDMI applies EC to the audio and control data is that errors in those channels are more noticeable to the user, whereas errors at reasonable rates in the video will mostly sneak by. The HDMI spec at http://www.hdmi.org/download/HDMI_Spec_1.3_GM1.pdf http://www.hdmi.org/download/HDMI_Spec_1.3_GM1.pdf is a great source of information about this.
- ErrantX 17y ago
  Indeed. However it uses TMDS [1] which is a "blind mans" error reduction technique. 1. http://en.wikipedia.org/wiki/Transition_Minimized_Differential_Signaling http://en.wikipedia.org/wiki/Transition_Minimized_Differenti...
  - wwalker3 17y ago
    Totally true. HDMI takes many steps to try to reduce errors to a reasonable rate. In practice, this rate is usually low enough to ignore, even with cheap cables. I was just making the point that there is indeed a progressive degradation in image quality with increasing error rate, even in HDMI.
- jcromartie 17y ago
  I've had this happen. You see what are called "sparkles" when you get a lot of failures (and it truly looks like sparkling glitter on your TV). It turned out to be the TV's connector more than the cable itself. The same $4 cable worked fine on a replacement set.
- 17y ago
ghshephard 17y ago
Clearly you've never had an Ethernet Cable that got caught in a door. Or was terminated poorly. Or doesn't have the insulator sheath under the crimp. Or run parallel to a set of Florescent light ballasts. All of these events can reduce performance on Ethernet without causing it to fail outright. There is a reason why every single TIA/EIA 568 cable plant is carefully tested for things like Near End Cross Talk (NEXT), Latency, Skew, etc.. There is also a reason why there is an entire _discipline_ dedicated to ensuring that the "Digital" signal not only has a channel, but a meticulously crafted one. (See: http://www.linktionary.com/t/tia_cabling.html http://www.linktionary.com/t/tia_cabling.html for details) To reiterates the OP - there is no "Digital Signal" - signals are analog in nature, and they need an analog channel to transmit them. That analog channel needs to be engineered carefully to get the lowest EBR (Error Bit Rate) possible. What's interesting is the Failure case of the Digital CODEC on the other end - some may reduce transmit rate in the presence of an increased EBR resulting from dropped packets. Or some may seize up and cease to function. In the degraded case, having a pristine analog channel from the transmitter to the receiver will certainly result in a better digital signal. There is also the issue of future proofing - We're installing an entire plant of Category 6a cable right now in one of our data centers for a gigabit environment - Category 6a is like the "Monster" version of Category 5e/6 - It seems like a douchey way to do a network install, except when you consider the following - (1) this cable plant will be in use for 10-15 years, (2) We're testing a bunch of Nexus 5010s that will likely make good use of that 6a for 10 Gigabit. So, in addition to passing _today's_ signal flawlessly, it will also pass tomorrow's. This might be an important factor if your HDMI cable is being run through hard to access cabinets/walls. Now, with all that said, it is still probably the case that the $150 Monster Cables (under normal circumstances) don't have a lower EBR than a $10 cable, but, in the face of RF interference, It may actually be a better performer. I don't know, but I wouldn't discard the possibility without a bit of research and education.
- lkjhgvbnm 17y ago
  But did you use audiophile, linear crystal aligned cables? And did you install them the correct way round? https://usa.denon.com/ProductDetails/3429.asp https://usa.denon.com/ProductDetails/3429.asp Presumably on ethernet you have to decide if you want the Tx or Rx signal to have the extra digital nuance?
ghshephard 17y ago
Note, it's traditional on HN to add the phrase [EDIT] when making substantive modifications to comments, particularly if someone has already responded to your original comment.
- pbhjpbhj 17y ago
  OT: The site should really help to enforce such niceties. When you edit you should get a "reason for editing" box.

mrcharles 17y ago

The point is not that you can use anything, the point is that you only need a certain level, and then it's good enough. All my HDMI cables are from monoprice.com, I don't think I paid more than $4 for a single cable, and I can't imagine what kind of EM interference I'd need to mess with them. I have so many electronics in my house I'm probably on a watch list.

deleted 17y ago

[deleted]

micks56 17y ago
Are the colors 0026FF and 8026FF the same? No, they are not. And the difference between blue (0026FF) and purple (8026FF) is a 1 bit error. You will see an image, but not the image your DVD told your TV to display. edit: This comment makes a lot less sense with the deleted comment removed.
- ramchip 17y ago
  It takes a lot of noise to alter the digital signal like this. If we're talking long distance, like a telephone line, the signal gets weak enough that it can happen regularly, but on the cable from the DVD to the TV the voltage drop is ridiculously low. Noise doesn't affect your signal by 4 volts unless you have a serious problem with your system.
  - micks56 17y ago
    Actually, I think that it takes the exact same amount of noise to flip a bit as it does to transmit a bit. Through the principle of superposition, if you transmit a 0 with X watts, and I transmit a 1 with X watts, our combined signal will be somewhere in the middle, which can cause a bit flip. I am not talking about voltage drop from end to end, which is a separate issue. I am talking about interference occurring adjacent to any point on the cable that you pick.

mseebach 17y ago

I think "It is digital. It either works or it doesn't" in the context of A/V refers to the quality of the converted analog signal - what comes out of the speakers or is visible on the screen. And the signal getting through can either work or not, no matter how well engineered the cable is, isn't that correct?

micks56 17y ago
But the reason why your digital TV shows the correct screen is because the cable transmitted the "digital" bits between your DVD player and the TV correctly. If you have a poorly made cable you will get bit errors. Electromagnetic interference from other A/V equipment could also cause bit errors. A well made cable with twisted pairs, proper shielding (few people do this correctly), and well formed connector crimps will prevent those bit errors. With bit errors, what your awesome Blu-Ray player decodes off of the Blue-Ray disc will not be what is shown on the screen (assuming there isn't bit error correction in the TV, etc.). And your speakers are playing an analog signal. Cable quality matters even more there.
- mseebach 17y ago
  > But the reason why your digital TV shows the correct screen is because the cable transmitted the "digital" bits between your DVD player and the TV correctly. If you have a poorly made cable you will get bit errors. Yes. Which is why the poorly made cable can be said to not work. > And your speakers are playing an analog signal. Huh? I've never heard of HDMI cables capable of carrying analog sound.
- oostevo 17y ago
  Yup, the correct signal might not get through if you don't have perfect shielding. And a speck of dust on a CD could theoretically ruin a whole song. That's why CDs (and cellphones, modems, and countless other digital devices) use channel encoding.[1] That way you don't have to have a perfectly noise-free signal to reconstruct the original information. I don't know that many specifics of the DVD or Blu-Ray standards, but I'd put money on them using Reed-Solomon or something similar. [1] http://en.wikipedia.org/wiki/Reed-Solomon_error_correction#Data_storage http://en.wikipedia.org/wiki/Reed-Solomon_error_correction#D... (Edit: forgot footnote)

GrandMasterBirt 17y ago

Ok when it comes to HDMI the goal was to always have good quality. The difference between an analog and digital is that digital ENCODES the information, it either gets there or not. The only thing the cable gives you is bandwidth. Analog is different. The signal is itself the image, so a poor signal = poor image. MAYBE if you have a projector projecting onto a movie theater screen will a better HDMI cable matter... maybe? because of bandwidth limitations if the sender is smart enough it might send info at a lower resolution. Other than that I can't see theoretically why a good HDMI cable will help. Also on my 42'' tv, I've yet to be shown a performance improvement when connecting my XBOX 360 via component or hdmi. It looks identical. And if HDMI is better than component, then I don't see a reason why you would ever need a good HDMI cable unless you are a movie theater and the theoretical problem does exist. Edit regarding bit errors... Lets assume that the cable you bought is a good quality cable. By good quality I mean most seem to be shielded and not cut and no shorts. This is a reasonable expectation. I've yet to see an argument for buying more expensive super gold plated uber network cables. Hey why is your network cable that handles SO MUCH DATA not gold plated shielded etc.?

micks56 17y ago
My network cable that handles all my data doesn't have gold plating or shielding because the cable as designed is sufficient to operate at Ethernet speeds, temperatures, humidity, etc. If you want to operate a faster network, or one in a harsh environment, you will be using shielded cables with gold plates and more twists per inch.

deleted 17y ago

[deleted]

lurkinggrue 17y ago

The real time to worry about the quality of those cables is when you go over 6 feet.

frou_dh 17y ago
Unless you are making your own cables, I don't see why. If the >6 feet cheap cable you bought doesn't work properly then it is faulty and you can get a refund.
- derefr 17y ago
  "The real time to worry about the quality of those cables is when you go over 6 feet," would make sense as something said to the cable manufacturer. Translated to consumer-speak, that would be "it's really quite hard to find cheap HDMI cables longer than 6 feet from a well-known brand." (Of course, shady brands will just sell the crappy cables and rely on people's innate laziness and stores with no-refunds policies.)
__david__ 17y ago
Not really, I have 2 $12 25 foot hdmi cable that work just great. I bought the cheapest one I could find because, hey, if it doesn't work I'm only out $12. But it's been working great for a couple years now.

ugh 17y ago

I guess the argument should have been that once you cross a certain threshold, cable quality doesn’t matter. That was of course also true for analog signals (human senses are only so good), but the transition from good signal to bad signal might have different characteristics with digital signals. While a image from a analog signal will only get noisier and noisier as signal quality decreases, images from a digital signal will first show artifacts and then just stop displaying altogether. That’s a rather sudden transition. One second the signal is there, the other it's gone. Something like that just doesn’t happen with analog signals. (I’m basing this on my experience with terrestrial digital broadcasting – could be totally wrong for HDMI connection but I doubt it.) I would guess that how sudden that transition is has something to do with the error correction and the codec of the signal. How many wrong bits can the error correction reconstruct? And, as soon as the wrong bits get past the error correction, how many wrong bits can the decoder handle and still reconstruct a image (albeit one with artifacts)? It would certainly be interesting to know how that problem was solved for HDMI connections. If you know the maximum bit error rates for your cables figuring out which are the right ones should be easy, given enough testing :)

lmkg 17y ago

There is still a qualitative difference between digital and analog signals. With analog signals, you can always get higher fidelity by upgrading components (until something else becomes the bottleneck). With digital, there are gradients of "wrong" but there is only one "right." Once you hit the threshold of bits not being flipped, getting more expensive and higher-quality components will not get you better-sounding playback. A digital cable can achieve literally perfect playback. Analog cannot reach perfection, which means it's always possible to improve. I'm not an electrical engineer so I don't know what the threshold of perfection is, but if the consumer reports can't tell the fancy cable apart from the Radio Shack equivalent of two-buck chuck, I'm not going to worry about it. On an unrelated note: this is a listing on amazon for 6 feet of digital audio cable for over a thousand dollars. Read the comments. Comic gold. http://www.amazon.com/Denon-AKDL1-Dedicated-Link-Cable/dp/B000I1X6PM http://www.amazon.com/Denon-AKDL1-Dedicated-Link-Cable/dp/B0...

blackguardx 17y ago

If a cable has an HDMI logo on the box, it is guaranteed to work. Specs are specs.

lkjhgvbnm 17y ago

>"Digital" signals are analog signals True that's why I reject TVs with a video chipset, I want a TV and a DVD player that uses valves for the video processing. I wonder how big an MPEG-2 decoder in valves would be?