HDMI (High Definition Multi-Media Interface) is the newest method for hooking up your audio video systems. When properly implemented, you can get the best possible connectivity between your new Blu-Ray player and 1080P TV. It is also the cause of a great deal of confusion, misunderstanding and unfortunately, problems.

What is HDMI? It is a protocol for transporting pure digital audio/video signals between devices in a manner that optimizes quality and resolution while also keeping it copyright proof (thanks Hollywood).  

In the “old” analog days, you would hook up your equipment with RCA jacks. If the connection was good, you got a nice picture and sound. If the connection was bad, you would get a snowy picture or poor sound. Even if you messed it up completely, you might at least have something. 

In the digital age, it either works or it doesn’t:  No picture. No sound. No control. Nothing.  To complicate matters, there are a number of variables which can contribute to the HDMI failure, making the cause difficult to isolate.

So why HDMI? 

Well a couple of reasons: 

  1. Picture & Sound Quality: All new TV’s, Blu-Ray discs and cable boxes are capable of increasing resolution and clarity. This increase in resolution dictates more bandwidth and ultimately a different type of cable and hook-up method that can handle the signals.   
  2. Compatibility between devices: Picture and sound resolutions are not standardized and come in varying formats…480i, 480P, 1080i, 1080P, 1080/24, 1080/60, and on and on… And unfortunately not every device is capable of each resolution. To get around this, the HDMI protocol includes a “handshaking” system where the devices talk to each other and match their best resolution capabilities. Here’s a typical conversation between Mr. Blu-Ray and Mr. 60” Plasma:

Mr. Blu-Ray Player: Hi Mr. 60” Plasma, Mr. Blu-Ray player here and I want to play this disc in 1080/24.  Is that cool with you?

Mr. 60” Plasma: Yeah hi Mr. Blu-Ray. No, I don’t like 1080/24. Only my bigger brother can do that. Can you send it to me in 1080i?

Mr. Blu-Ray: Ok I guess. Not as nice a picture, but here you go. Enjoy the show. 

  1. Control: We all wish we had more control and HDMI is lucky enough to say that it does. Inside the communication link of HDMI is a provision for devices to talk to each other. For example, the simple act of turning on your Blu-Ray player could trigger your TV to automatically turn on and go the right input. Pretty cool. 
  2. Copyright Protection. This is the biggie.  Hollywood is terrified of having perfect copies of their movies reproduced and subsequently sold by street merchants on sidewalks atop an old blanket. Not good for their image or profits. So, they imposed a system on HDMI to prevent unauthorized reproduction. Basically it requires the two devices to establish and maintain a dialogue the ENTIRE time picture and sound are being played. Specifically, the receiving device (the TV) requests to see a “key” from the sending device (a Blu-Ray player). If the key looks good, the show goes on. If not, the curtains come crashing down. This dialogue happens many times per second. Remember the conversation between Mr. Blu-Ray and Mr. 60” Plasma? Well, here is what their continued chatter looks like: 

Mr. 60” Plasma: Hi Mr. Blu-Ray, can I see your key please?

Mr. Blu-Ray: Sure thing dude, here it is.

Mr. 60” Plasma: Thanks, looks good.

Wait 100th of a second

Mr. 60” Plasma: Hi Mr. Blu-Ray, can I see your key please?

Mr. Blu-Ray: Sure thing dude, here it is.

Mr. 60” Plasma: Thanks, looks good. 

Wait 100th of a second 

Mr. 60” Plasma: Hi Mr. Blu-Ray, can I see your key please?

Mr. Blu-Ray: Sure thing dude, here it is.

Mr. 60” Plasma: Thanks, looks good. 

And so on and so on. Really boring guys huh? 

All of the above sound reasonable so why is there a problem? Let’s look at the pitfalls of each:

 Picture & Sound Quality: Frankly this is the best part of HDMI and rarely is there a problem with how good the audio and video can be using this medium. Score 10 for HDMI! 

  1. Compatibility between devices: The whole idea of the two devices working together to give you the best resolution sounds great right? Most of the time it is. But the issues it can create are irritating. When you start up your system for example, you will have this black screen that says “no signal” even though you get sound.  And forget fast channel surfing: each time you change channels, Mr. Blu-Ray and Mr. 60” Plasma have to re-introduce themselves and negotiate a resolution. This means that you could get a blank screen for 3-5 seconds between each channel change. Score -3 for HDMI. 
  2. Control: A little is good but too much is overbearing. Imagine keeping your cable box on to record a show while changing over to Blu-ray to watch a movie and the TV won’t let you? Or how about using the cable box to listen to one of the music channels on your stereo but you can’t because when you turn off the TV, the cable box shuts down. And there are many other little maddening scenarios which will leave you thinking that your system is possessed. Score -2 for HDMI. 
  3. Copyright Protection: Remember I said this was the biggie? Well it is. If any one of the hundreds of boring conversations between Mr. Blu-ray and Mr. 60” Plasma TV gets interrupted, even just one, your screen goes blank. Nada. Zero. Nothing. And it could take 5-10 seconds for it to come back during which you will likely switch channels etc. trying to “make it work” which unfortunately makes it worse. Score -5 for HDMI. 

How do get around these issues?

  1. Use great cables! HDMI cables will not only get you better picture and sound quality, they will help to make sure Mr. 60” Plasma and Mr. Blu-ray keep talking. Think of the cable as a marriage therapist.
  2. Install the cable correctly: Any little crimp or extra pressure on a cable will cause a breakdown in communications. You know what that means.
  3. Use compatible equipment: If you are insistent on building the system yourself use  devices from the same manufacturer.
  4. Stabilize your power using a UPS: Any slight variations in power will impact the conversations between Mr. Plasma and Mr. Blu-Ray.  
  5. Do NOT attempt to run HDMI long distances (beyond 18’), regardless of what the specs say. Unless you are lucky, it will not work right.

 

Leave a Reply

Your email address will not be published. Required fields are marked *