Does signal carried over HDMI degrade as cables lengthen?

Discussion in 'Home Theater PCs & Equipment' started by nerr, Aug 25, 2008.

  1. nerr

    nerr Limp Gawd

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    I'm curious because I may be interested in buying 30+ feet of HDMI cable to hook up my PC to the family HDTV in another room, by routing cable through the basement. Does HDMI signal degrade over long lengths of cable? Would it be possible to route a 1080p video signal from my PC's Blu-Ray drive to my HDTV with minimal loss in quality? Simply plugging in a cable to carry audio and video signals would be much simpler than constantly moving my PC to the other room to watch Blu-Ray movies with it. I unfortunately won't be able to game with such a setup, because both my keyboard and mouse are wired, but it could work for movie-watching. Any information would be greatly appreciated.
     
  2. Syndicated_Death

    Syndicated_Death [H]ard|Gawd

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    I would say no since it's digital but I can't be for sure.
     
  3. kumquat

    kumquat [H]ardness Supreme

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    Electrically speaking, the signal degrades, absolutely.

    But the data doesn't.

    As long as the data is getting there, nothing else matters. Think of it like Wi-Fi. The signal strength degrades the farther away you get, but the signal is still there and you can still maintain the same data rate, until you can't anymore.

    As long as you're getting a picture without major artifacting or sparkles, then the signal is fine. This isn't analog.

    I use a 50' Monoprice HDMI cable to connect my PC to my HDTV. Works great.
     
  4. w1retap

    w1retap [H]ardForum Junkie

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    Anything over 20 feet, I'd say go with the top quality Monoprice cable. They're cheap enough, and they're built well.

    The "since it's digital" argument is a myth. The cable quality does matter, especially in the case of 1080p video. It also depends on the devices you run too. Some are more sensitive than others, and they might not pick up the signal on the other end if it's lost due to attenuation. It can result in little white pixels being blipped on the screen, blocking, or even no signal at all. I've seen it happen, and I have first hand experience with a crappy HDMI cables that came with cable boxes from Comiecast. Another outside influence that effects the signal is EMI. If you have an EMI source close to the cable, it can really effect your signal adversely if the cable isn't built with quality shielding.
     
  5. TroubleMagnet

    TroubleMagnet Gawd

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    I'll throw another vote to monoprice for your HDMI cable needs as they are good quality and inexpensive. I've had great luck with them, using one of their 15' HDMI cables for the run to the projector and one of their DVI -> HDMI cables to connect up the PC to the switcher. The digital signal is a bit more robust than the analog but you still need a decent quality cable. One of my friends also has a 30'+ run using a monoprice cable and it works fine for him.
     
  6. xtvrzero

    xtvrzero [H]Lite

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    +1 for monoprice cables, I have a 30' dvi to hdmi and it works great.
     
  7. Archaea

    Archaea [H]ardForum Junkie

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    I've read extensively on this on forums and such and the end result is --- there is no real length end cap that is specific enough to say 22' feet is okay, but 23' feet fails. There are some scientific studies on this though and you can find some of these online. The result of too long a cable/degraded digital signal is "sparklies" little white "snow" pixels from what I've read.

    A general safe rule is 20 feet without a repeater for 1.3 HDMI, 1080P signal.
    If 720p is all you are outputting you can get away with longer, and there is always variances in equipment.

    Monoprice.com has cheap cables as others mentioned and I've ordered there for years. Read the reviews on the cable you pick out and you'll get an idea of what worked for who with which setup :)

    Signal DOES degrade over distance --- in response to the second poster. If you don't know the answer to a question why would you make/guess one up?
     
  8. Syndicated_Death

    Syndicated_Death [H]ard|Gawd

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    would it have made you feel better if I acted like I did know? I find that admitting I don't fully know the answer to something is a lot better than bullshitting.
     
  9. w1retap

    w1retap [H]ardForum Junkie

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    Yeah, I'd say a Prius can drive 3746 miles before it refuels, but I can't be for sure..

    I mean, come on, just look how that sounds. :p
     
  10. Syndicated_Death

    Syndicated_Death [H]ard|Gawd

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    yeah the difference is I wasn't wrong. nor was I making any gross over statements. I made an educated guess BFD.
     
  11. PolygonGTC

    PolygonGTC [H]ard|Gawd

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    The simple answer is, yes. Digital or no, it doesn't matter. It is running on a copper conductor and the longer the cable is the harder it is to maintain the signal and you become susceptible to artifacting and total loss. I wouldn't go over 25, at the most, without repeaters.
     
  12. wildfire99

    wildfire99 Gawd

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    I would. :D

    The fun thing is, you can buy a fancy 35 foot or 50 foot monoprice cable, try it, and if it fails, just buy an amp or something. My premium monoprice 35 footer has worked flawlessly with everything I throw at it. I'm not so gusto as to do a straight run of 50 like many people, but even then you hear lots of success stories at 50 feet with the good heavy gauge monoprice stuff as well.
     
  13. nitrobass24

    nitrobass24 [H]ard|DCer of the Month - December 2009

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    Yes it does not matter if its a cat5 cable, hdmi, svideo digital or analog you will suffer from signal attenuation over long distances. That being said if you have a cable of decent quality anything under 50 feet you should be fine. over 50 feet your going to want high quality cables and possible signal amplifiers/repeaters.
     
  14. Archaea

    Archaea [H]ardForum Junkie

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    Where are you pulling this 50 foot number?

    As stated before most scientific tests I've read say 20-25 feet max. Some of these 'studies' are posted by user comments in the individual cable reviews on the monoprice site. Sounds like someone saying they notice no signal dedgregation on the 250 foot VGA cable connecting to their projector at church. Well perhaps not on 3' letters with a simple monocolor background, but if you compare a six foot vga cable with a 250 foot cable side by side on a detailed image you'd notice a huge difference.
     
  15. kumquat

    kumquat [H]ardness Supreme

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    Like I said, my 50' Monoprice cable works 100% perfectly on my 50" plasma.
     
  16. TroubleMagnet

    TroubleMagnet Gawd

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    There is not going to be any consistent maximum length for HDMI cabling since it will depend on the cable, driving device, receiving device and what resolution is sent (the standard goes up to 1600p). Right now most people are going to max out at 1080p for long cable runs since they are going to a HDTV display, typically the 1600p displays are computer displays and are not going to have long cable runs. I'd guess a fair number of the tests that are getting the lower max cable lengths are testing at the maximum cable bandwidth (which runs at a higher rate, lower resolutions run at lower rates) and so you will be able to get to longer lengths at the lower resolutions. Category 1 is up to 720p/1080i (74.5 MHz) and Category 2 is up to 1600p (340 MHz) according to the HDMI wikipedia entry. In theory the manufacturer should be testing their cables to make sure they can function at the category rating they advertise, if any. Sadly a lot of them have gone to advertising 1.3a compatibility, which is dumb since HDMI 1.x compatibility only matters for the driver and receiver, not the cables. For the cable you only need to care about category 1 or 2.

    Bottom line: If you are running 1080p and can find a cable that is category 2 certified by the manufacturer then you should be fairly sure it will run error free at that length. If not you should definitely return it, even for a long run.
     
  17. PolygonGTC

    PolygonGTC [H]ard|Gawd

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    Yes, there are to many variables to say there is a definite length. One thing you forgot to mention TroubleMagnet, which is location specific, and that's interference. There could be more interference in my home than in yours, wildfire99 & kumquat, therefore I can't get much more than 25 feet on a 1080p signal.
     
  18. cnealjr

    cnealjr Gawd

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    Short answer = yes.

    Long answer = yes, but it depends on your location, as discussed above.

    You can always try a quality cable from monoprice and see if you get satisfactory results. If not, get a repeater/amp and give that a shot. With HDCP, I am a fan of as few stops along the way as possible between the display and the source, that way you are more likely to complete the "handshake" successfully allowing the display of your content. When you start adding more devices, such as amps or even your home theater a/v receiver, you can run into trouble with the handshake process.
     
  19. TroubleMagnet

    TroubleMagnet Gawd

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    Yup, interference can definitely factor in. You should be able to get rid of most of it by using a shielded cable, but those are hard to get to 100% effectiveness since even with a well designed cable there typically are going to be some holes at the connect to the devices, and the devices themselves will have varying levels of shielding as well. You live next to a radio tower? :p
     
  20. PolygonGTC

    PolygonGTC [H]ard|Gawd

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    Not right next to, but there are some close by. Cell towers to be exact.
     
  21. nerr

    nerr Limp Gawd

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  22. w1retap

    w1retap [H]ardForum Junkie

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    Yup, the CL2 22ga wires are definitely good. I'm using a few of them, and I've had nothing but a good clear picture from them.
     
  23. bigdogchris

    bigdogchris [H]ard as it Gets

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    My $6 HDMI cable I bought off ebay works great. Picture is really good.
     
  24. Easykill1978

    Easykill1978 Limp Gawd

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    30 FEET is too long, it is recomended at 15 ft ~20 to but an amp on the line, no matter the quality of the cable. i just use a splitter (hdmi 1.3 certified) that gets a 5 volt dc power supply and i got no worries. mine cost me 15 bucks..
     
  25. w1retap

    w1retap [H]ardForum Junkie

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    30 feet is not too long.. I'm running a 35 foot monoprice HDMI cable for 1080p video in my home theater just fine. You can even do a 50 footer just fine with their CL2 rated cables.
     
  26. Archaea

    Archaea [H]ardForum Junkie

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    ^ that HEAVY cable is exactly that. When you receive that cable you'll realize that the terminal ends put a lot of weight on the HDMI jacks and may need to be braced in some way so as not to damage the connectors. Some of those bigger wires are the equivalent size of 4 guage power wire or more. You'll see what I mean.
     
  27. w1retap

    w1retap [H]ardForum Junkie

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    That's one of the main reasons I hate HDMI cables. The connectors blow. If it was like DVI with the screw in chassis plate, you wouldn't have to worry about terminal damage as much. Whoever designed the HDMI connector standard was a dolt.
     
  28. pre1014

    pre1014 Limp Gawd

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    Gizmodo did have a lengthy test pitting the monoprice cables up against monster cables.

    http://gizmodo.com/tag/hdmi-cable-battlemodo/

    In their testing the 50' monoprice cable did have some issues. I don't really quite know how reputable gizmodos testing lab is (ha!) but it looks to be legit tests.
     
  29. wildfire99

    wildfire99 Gawd

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    The monoprice "port savers" work well for moderate strain-relief on their heavier gauge cables. They're even nice just for removing the need to plug things in at perfect 90 degree angles. They're worth the $3 or whatever they are now.
     
  30. nerr

    nerr Limp Gawd

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    Hey guys, I know it's been a while, but I ended up ordering that 40' Monoprice cable and am using it now. It works wonderfully! Highly recommended to anybody interested in carrying an HDMI signal over a long distance or between rooms.
     
  31. Chase023

    Chase023 n00b

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    Cool, glad its working for you, tho for my peace of mind, I would of probably put a repeater at 20' or so.

    I am betting for shorter cables there isn't too much of a difference, but for the longer ones as you mentioned (50' and etc), I am not too surprised with the results.

    Personally, I think for the average user, I think monoprice cables or most decent cables do great. But I think it's all relative.

    It's like say if you had something like a $25,000 entertainment system or so, would you be using Monoprice cables or something like Monster or like Bettercables and other higher end ones?
     
  32. wildfire99

    wildfire99 Gawd

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    I used Monoprice extensively with my $15,000 system. I always say, copper is copper... the electrons don't know the difference and I have no intention of telling them. As long as the gauge is sufficient to allow unrestricted passage of current (and capacitance isn't obscene) then it's all the same, IMO.

    The only place I got picky was XLR interconnects... I made some by hand because nobody had the nicer black Neutrik ends without charging a fortune. That was a usability and sexiness factor, not a performance one.

    I would say from that experience that you're going to have more issues from room effects than you will from your wires. And I've tried all the fancy wire types, materials, the cat-5 cords, magnet wire, etc (but admittedly, nothing cryo-treated nor the fancy flat ribbon cables). They sound different but that was never in a good way. The thing I could never get around is how people get all wrapped up in exotic cabling and then plug into their run-of-the-mill house wiring or into generic wiring inside their speakers.

    I've worked on very exotic setups wired to the hilt with Monster and I have to say that every time it's a serious PITA because it's overbuilt and many of their RCA ends require vise-grips to get off of connectors. Yes their materials are nicer, and if I was the CEO of the company or someone who could get their stuff free or at cost I'd use it extensively, because you're simply going to have better average build quality. I would expect, defective cables aside, performance to be the same when wire gauge is the same be it M for monoprice or M for monster.

    If and when I do reassemble a high-ticket system, even a $25k one, I would have zero hesitation in wiring it up again with Monoprice and Dayton brands. Unless I had some exotic need for vampire-repelling silver cables, I wouldn't even consider Monster/Better/et.al. Remember, people who have money to burn usually have it because they're not wasting it. :)

    If I bought the above cables I would be doing so because construction and bling factor are more important to me. Not because of any perceivable performance difference. But more power to those who buy boutique. I might get into it some day myself and make cash on the side building out fancy audio gear.

    I don't want to put down anybody who believes in cable makers, that's not my intent and I think you should do what makes you happy, since that's the goal of a hobby. My intent is to say to people with Monoprice budgets, you're not missing anything.
     
  33. figgie

    figgie [H]ardness Supreme

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    yawn

    no such thing.

    Again. It all is dependant on the environment.

    I have a PS3 connected to an Infocus IN82 via a 30 foot HDMI.

    1080p @ 60 hz. No Problems. No Artifacting. No Macroblocking. This is both games AND blu-ray watching.

    Where did I purchase my 30 feet of cable? Microcenter.

    BTW My system is the following ;)

    Infocus IN82
    Klipsch THX Ultra 2, 5.2 system (two subs and the other 5 speakers).
    KA-1000-THX
    Integra DTC 9.4 -> 2 Crown XLS 602
    PS3 (Blu-Ray)


    In total , about $17,000 worth of equipement.

    Wiring?

    200+ ft CL2 rated speaker wire from Lowes.
    30' HDMI from Microcenter
    Power = Stock
    RCA = Custom built canare cables by me.