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Since this is a industry area, I would like to get some type of response as to why they choose to go this route. To me it is a huge step back from the robust design of the DVI cable. Over the last week, I noticed some issues with my TV and Cable box, hooked up via DVI with a NXG HDMI adaptor into the cable box. I started getting green sparklies off and on. Thinking is was the cable, I turned on my projector and it was clear. So I rattled the connector and the picture got even worse, and finally the handshake broke, so I got no picture. I had a monster adapter and swapped it, and volla it fired back up crystal clear. I looked at the adaptor and it appears to have bent due to the weight of the cable. So my question is, why was this not designed to have a better connection such as the DVI or something that would clamp down so it would not be as stressed. I just recently replaced my M1/DVI cable with a 35 foot Monoprice HDMI that is really thick and stiff, so I am now worried that over time it will either stress the connector, or worse yet the connector on my DVD player/ or PS3.
 

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Wallmart shopper.

The HDMI cable/terminal was designed for the 6' single source to disply by the AV novice market.

They used the USB cable as the guide line.

Plaes note that most pull-out problems are caused by heaver larger gauge cables (not what the standard was planned for).
 

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The DVI cable was not a great hit in the consumer electronics market due to its size (large overmold that would extend out quite a bit from the back of a TV for example, and large footprint due to dual link and analog VGA pins) and the retention screws. You might notice that the vast majority of CE connectors use friction retention, and for good reason. There are times when a consumer or installer will want to pull out a component (like an AV receiver) such as when cabling up a new component. If a cable gets caught while the component is being pulled, you have 2 choices:

1) the cable connector reaches a reasonable retention force limit, and then pops out, or

2) the cable connector has a very high retention force limit (practically infinite if using screws), and thus the weakest link now becomes the mating female connector in the component.


Obviously, one would prefer to have the cable pop out before the back panel of your AV receiver rips out.


The HDMI cable & connector does have mechanical requirements related to the retention force, and other mechanical robustness specs. In fact, all HDMI connectors undergo a destructive test to validate their compliance. Quality connectors are also designed to undergo thousands of insertions as well while retaining their retention forces on all the pins.


Unfortunately, we have seen some instances where non-compliant connectors make it into the market, and we do our best to monitor and correct such issues that are found. You can look at the hdmi.org website to see what brands of cable makers are HDMI adopters (although it's possible that an unlisted manufacturer is shipping a compliant cable). Also, looking for the HDMI logo is a good idea since the usage of the logo requires that the product has undergone compliance testing.
 

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To answer the OP, yes the HDMI connector is the worst mechanical design ever. What it is trying to do electrically is great, but the mechanical design is terrible.


To start, relying on retention force has several problems, the biggest being that it is reduced every single time the connector is plugged/unplugged. Simply adding a positive mechanical attachment with two side screws would be a drastic improvement.


Also, the cable was NOT designed for the 6' single source novice. This was intended as a high-end design that could still be easily used by the novice. So what happens is that you use a quality cable with some degree of bulk to the end and you start having internal connection problems. Several designs have already had to move away from the surface mount version of the connector due issues with lifting pads and broken connections.
 

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Quote:
why was this not designed to have a better connection such as the DVI

Price? Bulk? Tradition?


Look at the back of a typical receiver these days -- the biggest problem is where to put all the connectors! Imagine if those four HDMI slots were DVI instead.

(I totally believe receivers could be half height if they didn't need all that real estate in the back)


My solution is to de-stress using duct tape. It goes behind the equipment, so nobody will notice. And it's plenum rated, by design.
 

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What a horrid connector. HDTV makers aren't helping. My Samsung has this flimsy thing that I have to wiggle to get a good picture. At least they should secure the connection to the chassis and not just hang it off the circuit board.
 

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Based on my experience, which is an analog chip designer who once designed an HDMI 1.2a compliant receiver IC, most of the issues with HDMI relate to interoperability. I found that most of the interoperability issues relate to the HDCP protocol. That's essentially the copy protection that "scrambles" the data going over the wire. It has to do an authentication "handshake" over an backchannel to get things going. When it doesn't work, you'll see things like a picture that "blinks" on and off, or perhaps "snow" on the screen. Eventually a source may just give up and stop transmitting. Different manufacturers had different interpretations of the protocol. Unfortunately, HDCP was never part of the original compliance test procedure. It is now. HDMI, to their credit, is addressing that. But it doesn't fix legacy devices that are out there, and behave poorly.


HDMI is an improvement over DVI in that it introduced actual compliance test. To make a DVI part, you essentially just have to claim it's DVI compliant. No-one will check the validity of that statement. So, as a result, many DVI links didn't work well. That's why it's relegated essentially to computer video. I shouldn't divulge what's in the HDMI compliance test specification but suffice it to say it enforces better designs. The HDMI connector does improve electrical characteristics over DVI. I can say that based on network analyzer measurments that I've seen. As for its mechanical quality, that remains debatable.


HDMI 1.3 and up have better recommendations, such as cable termination on BOTH the source and sink ends and reference equalizer designs. The equalizers boost high frequencies which get attenuated over long cable lengths (HDMI is digital, so you'd think the actual electical signals on the wires are "square" waves. But put that through 10+ meters of twisted pair copper wire and see what it looks like! The loss of high frequency information "rounds" off the edges, and they shift in time a bit. This is what causes errors at the receiver - it "sees" a high where it should be a low or vice versa. Classic serial link bit error stuff. EQ's can fix that). Electrical transmission lines (any kind of cable) also have reflections. Electical waves are similar to sound waves - when they move through a medium (wire) and encounter an abruptly different medium (something on a chip) there will be a reflection (like a sound echo). To fix that, transmission lines are terminated in what's called "characteristic impedance". You've seen that before, 75 ohms is standard for video, 50 ohms is standard for radio, 100 ohms is standard for ethernet (cat5) cables. But, a reflection can happen on either end of the cable (source end or sink end). So it's realy good practice to terminate both ends. HDMI originally only used sink end termination. I think 1.3 and up allows for source end as well, which is a big improvement. My background prior to HDMI was in even higher speed serial links (SerDes) where double termination is the rule of the day.


So as time goes on it will get better, both through improved standards and improved compliance testing.


Another thing to watch, though, is wireless HD connectivity. Viable technologies exist. I think one company already has a design win. After re-hooking up all my AV equipment last weekend, let me tell you it would be a welcome change!
 

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I agree. I lost one of my output ports on my Marantz 6003 I dont have warranty
. I have become careful after that. Every time I unplug I use a flash-light and check if the connector is fine.

I hope they change the design soon. Another solution I have thought of is use an intermediate adopter in between. Never remove the intermediate adapter just disconnect the cable only. This way the receiver connector is fine.

Most of the time it is the physical dimension of the connector that causes the problem. Every time I plug and unplug the pins get dislodged from the center piece.

Here is a diagram of what happenes(only the middle piece which has the contacts)

--

--------

| |

--------

I press the connectors down everytime using a watch screwdriver.
 

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I'll chime in as I really dislike the lack of any strain relief for a heavy HDMI cable.


This is reminescent of the SATA connector for PCs. What was supposed to be an upgrade to IDE, it was a couple steps back for connector (component side) durability.
 

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Quote:
Originally Posted by BigMike66 /forum/post/17122497


I'll chime in as I really dislike the lack of any strain relief for a heavy HDMI cable.


This is reminescent of the SATA connector for PCs. What was supposed to be an upgrade to IDE, it was a couple steps back for connector (component side) durability.

Here's help: http://stereophile.com/musicintherou..._the_round_37/
 

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Really, how hard could it have been to integrate some kind of locking mechanism? You would think they would design the male end to feature two buttons that would release it from the socket when pressed into.


Maybe by 1.7?
 

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I agree a cable you can screw down like a DVI would seem to make more sense, given that the average user is not frequently connecting and disconnecting the cable as they would with USB. I suppose the HDMI people had laptop computers and camcorders in mind when they originally designed the connector. I can see the advantage of an easily removable, compact connector in that context.


I really think the CE manufacturers bear much of the blame by not making the female connectors robust enough. Can't imagine it would be that difficult or expensive to use stiffer metal rather that the flimsy steel you typically see that gets bent and reamed out by the weight of the cable. And yes some of the cables these days are unnecessarily thick and heavy.


Of course the major flaw is not the connector itself but HDCP. which is the source of most people's problems. HDCP was overkill and botched from its inception and only recently are we seeing most of the handshake problems solved in newer equipment. But don't get me started. I talked to a Comcast installer who recently hooked up my cable and he told me they get a huge volume of complaints from customers who can't get HDMI to work. In fact. if you order a HD box in my area, they will bring you a Motorola with the HDMI output disabled in a way that you can't even enable it in the service menus and hand you a set of component cables. You have to specifically ask for an HDMI capable box.
 

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Quote:
Originally Posted by JohnFR /forum/post/17211451


I agree a cable you can screw down like a DVI would seem to make more sense, given that the average user is not frequently connecting and disconnecting the cable as they would with USB. I suppose the HDMI people had laptop computers and camcorders in mind when they originally designed the connector. I can see the advantage of an easily removable, compact connector in that context.


I really think the CE manufacturers bear much of the blame by not making the female connectors robust enough. Can't imagine it would be that difficult or expensive to use stiffer metal rather that the flimsy steel you typically see that gets bent and reamed out by the weight of the cable. And yes some of the cables these days are unnecessarily thick and heavy.


Of course the major flaw is not the connector itself but HDCP. which is the source of most people's problems. HDCP was overkill and botched from its inception and only recently are we seeing most of the handshake problems solved in newer equipment. But don't get me started. I talked to a Comcast installer who recently hooked up my cable and he told me they get a huge volume of complaints from customers who can't get HDMI to work. In fact. if you order a HD box in my area, they will bring you a Motorola with the HDMI output disabled in a way that you can't even enable it in the service menus and hand you a set of component cables. You have to specifically ask for an HDMI capable box.

HDCP is the only reason we have the awful HDMI cable.


As for Comcast dsabling the HDMI connections - that's a bit too far, even for someone like me who hates HDMI.
 
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