Zee's "I got bored and compared HDMI cables" thread.

Discussion in 'Audio Visual' started by Zee, Sep 16, 2011.

  1. Diode

    Diode Member

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    HDMI 1.4 spec cable capable of doing 10.2 Gbit/s (even the cheap ones need to achieve this throughput to be 1.4 spec)

    1080p (8-bit per channel) raw decompressed video frame frame uses 1.24 Gbps of the cables bandwidth.
    4k (12-bit per channel) raw decompressed frame uses 3.82 Gbps

    If you buy any modern HDMI cable it has more than enough bandwidth to account for any error correction required due to any signal loss happening on the HDMI cable even when transferring raw uncompressed video data.

    Now I'm not sure if the HDMI protocol compresses any of the data for transfer. But even if you factored that the blu-ray player would decompress it's frames and send them raw over HDMI you would need a pretty bad cable before you see image quality issues.

    Edit: from HDMI.org "One of the advantages of HDMI over other connection technologies is its enormous carrying capacity, which makes compression unnecessary." So it looks like HDMI does indeed transfer raw uncompressed video data.
     
    Last edited: Oct 16, 2011
  2. Space Hi-Fi

    Space Hi-Fi Member

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    Wow, great thread Zee!

    I haven't been on here for quite some time so this is the first time I have seen this thread. Admittedly, I have not yet had a thorough read (will do so soon) but even at first glance I can see how thorough this is.

    Love your work! :thumbup:
     
  3. Space Hi-Fi

    Space Hi-Fi Member

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    Yes, completely agree. The wire gauge is most definitely one of the most important factors. However, there are of course other attributes and factors that can alter performance (for better or for worse) over longer distances.

    I hope you don't mind me asking, which 22AWG HDMI Cables did you go with? Also, what lengths are you running?
     
  4. FFC

    FFC Member

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    So I recently purchased two cheap HDMI cables. However they intermittently lose signal (sometimes they work, for a short period of time - the picture then goes all wonky and signal is lost completely) when plugged into my brand new RX-V671. I don't have the latest firmware (1.13 vs 1.16), could this be an issue or are the cables just duds?

    I don't have any issue with any of my existing cables.
     
  5. OP
    OP
    Zee

    Zee Member

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    Sounds like dud cables to me.

    Z...
     
  6. FFC

    FFC Member

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    I'll try them not plugged into the receiver and directly from fox/xbox into the TV and see if it makes a difference.

    Bit odd that both of them don't work though, no one else has reported problems in the sponsor thread.
     
  7. poleposition

    poleposition Member

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    What always gets me is that differences can be so small at times that once you start watching a film unless you have 2 movies going at once you will never know what it was supposed to look like, so even the cheaper one could still give

    Especially when a difference is small enough that it would require measuring devices.

    I found these tests very good indeed. Well done thanks for taking the time to do them.
     
  8. BlueRaven

    BlueRaven Brute force & optimism

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    Could be a batch problem. The cable itself is probably fine, the connectors will be the problem (hence the picture coming back for a time after you reseat the cable).

    This does raise one relevant point... going for the cheapest bargain-basement leads you can find does not always provide the best value, as the materials used in the dirt-cheap cables are often very poor and quality control is non-existent. Sure, if the cable enables a handshake and passes a picture you might not see the difference in image quality but will it work flawlessly every time, and for how long?

    I'm not advocating spending $400 on a Monster or Audioquest cable, but dropping an extra $20 for something with reasonable build-quality could save yourself hassle in the long run.
    Most of the nicely-packaged "generic brand" cables sold for $20 - $30 by Jaycar or many online retailers would seem to be perfect in this regard. Ok, you're paying a fair markup, but at least they won't fall apart after two connect/disconnect cycles.
     
    Last edited: Nov 21, 2011
  9. FFC

    FFC Member

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    Yeah I am going to bin the cable that isn't working (the one plugged into the xbox is working fine, so no dramas there) and go to jaycar and get a new one.
     
  10. OP
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    Zee

    Zee Member

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    Which Jaycar? I'd suggest Adelong Computers (if you are near the city) instead, or just ordering from someone reputable online. Jaycar are quite pricey these days...

    Z...
     
  11. FFC

    FFC Member

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    Lane Cove/North Ryde area so not really. May just order one online. We'll see..
     
  12. Damn_Good

    Damn_Good Member

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    I've been smashed with this before. I got a "free!" HDMI cable with the purchase of a certain component one day. Took me two Xboxes and a reciever before I realised that the pins in it were stuffed and were mutilating the HDMI ports on my other gear.

    I ended up throwing all of my HDMI cables out just in case I'd used them on one of the mutilated ports and had in turn been bent and would thus continue to damage my other gear if plugged in. Painted all the damaged ports on the components so I knew not to use those ones again and replaced the HDMI cables. I was pissed.
     
  13. BlueRaven

    BlueRaven Brute force & optimism

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    Wow, that sucks man. I've seen plenty of bent/damaged pins in cables before, but never one that would actually damage a socket too... although I shouldn't be surprised I guess, the socket contacts are just as fine and flimsy as the ones in the plugs.

    As has been stated in this thread already, HDMI is actually a pretty godawful design from a mechanical perspective. One of the problems I find is that there is often very little physical 'feel' to indicate a positive connection unlike, for example, a USB plug which gives a very obvious feeling of good contact. The poor tactile feedback for a good connection means you are less likely to notice a bad/damaged connection, keep plugging/unplugging it while trying to diagnose the issue, and probably end up damaging the socket too.

    Some kind of locking connector would also have been nice for us custom AV/integration guys. Oh well, better luck next time I guess...
     
  14. schmoove

    schmoove Member

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  15. Cadbury

    Cadbury Member

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    To me, not all cables are created equal. When i connect my HTPC up to my projector using a 1.8m hdmi cable it works fine. However, when i use my 10m cable, nothing displays. This is because the EDID negotiation between video card and projector has inadequate signal strength. A lower loss 10m cable fixed the issue. As did using a different video card which wasn't so fussy about EDID signal strength.
     
  16. dakiller

    dakiller (Oscillating & Impeding)

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    That is not what is claimed by those who say that the picture quality is 'better' with expensive cable A Vs regular cable B. The claims are that is is brighter, crisper, more natural, more blue, more red, whatever adjectives videophiles use, not that the cable works at all. The question is then can these differences be measured, when any knowledgeable person would say that the signal is digital information and is either 100% correct or obviously not, so can someone say subjectively that they can tell the difference between one and another.
     
  17. Diode

    Diode Member

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    Is everyone aware of the new HDMI 2.0 standard? The cables are now rated at 18 Gbps which means they are now capable of delivering 4k video at 60fps.
     
  18. OP
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    Zee

    Zee Member

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    That is exactly the point. I always use high quality cables for installs, not for image quality, but for the knowledge that it'll work. High quality doesn't mean highly expensive, however...


    Z...
     
    Last edited: Sep 16, 2013

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