How Dynamic Headroom Improves HDMI Installs

Not a very informative article.  The article basically said “make sure you set things up properly”.  Telling use “to increase the water in something, you add water” is a waste of electrons.

A few “how to’s” would make the article have some use.

You are leaving out the core principles of why an all digital signal path is better.

You are essentially transmitting 1s ands 0s WITH ERROR CORRECTION ALGORITHMS.  Most all HDMI components available now (1.3 and above) have signal EQing built-in to compensate for long runs.  AND today nearly all HDMI switchers ARE ALSO REPEATERS.

Let’s put it this way, in my system I am using a mix of basic and higher quality(but reasonably priced) HDMI cables.  I have never had an issue with a signal not locking or sparklies (most likely what you will see if things are not working correctly).

HDMI was never meant for 100m installs.  If you are doing that, then I would have even bigger issues with the installer I hired.

Wow - this guy has no idea what he’s talking about.  Expensive cables are a waste of money.

Yes! You need to adjust azimuth, skew and elevation of your HDMI cable in case weather conditions will change to less ideal.

How much did Noel Lee pay you to write this article?

I so hate to see a legitimate website publish such a bunch of technical garbage. Comparing a highly variable, weather and solar dependent satelite signal to a controlled setup like an HDMI cable is just a demonstration of the author’s ignorance. By the way, my profession is to produce test and measurement equipment for the wireless communication industry, as well as for wired LANs. This guy is trying to waste your money.

@ Mark R: Keep your day job.

I agree that this article is totally useless.  Comparing HDMI signals to satellite signals is like comparing apples to toilets; which is exactly where this article should be placed.

What a load of snake oil, cepro is a joke, avsforums is a joke, and high end snake oil has ruined almost everyother audio/video forum out there, talk about trolls!

I agree, Wow, but this is the first junk article I’ve seen posted at AVS. Hopefully they will tighten their editorial review process. I am extremely disappointed in them but won’t paint them with the “troll” brush just yet.

Ok folks, let’s take a step back…

Jeff’s analogy of aligning a satellite dish to HDMI performance is simply an, “analogy.”

Let me give you another analogy that you all may relate to:

Let’s say you have a client that has purchased a 100 WPC stereo amp or receiver, and wants it to feed 4 different zones within the home with independent volume controls for each zone. The original 100 watts of the amplifier will lose, “X,” amount of power once it is run through the necessary speaker selector box, the amount of wire run, and every volume control. Depending on the gage of the wire, you will typically lose 5-10 watts of power for every 100’ feet of wire run, 3-5 watts for every volume control, and at least 5-10 watts going through a 4 zone passive speaker selector box. This is due to the impedance and amperage the specific amp can deliver or is designed to handle. That also explains why Niles, Russound, Sonance, etc., speaker selector boxes have a, “Protection,” button on them… it’s designed to prevent the amp or receiver from dropping below 4 ohms which in turn will make most inexpensive stereo receivers/amps over heat and shut off because they cannot handle the load.

Another simple analogy is that all amplifiers have a, “S/N,” (signal to noise ratio). I know this is basic audio 1.01 knowledge, but S/N is a ratio of how much signal to how much noise an amplifier puts out or can deliver. It is also a ratio of the, “dynamic headroom,” the amp can deliver. The higher the dynamic headroom you begin with, directly dictates how much power/wattage will finally be delivered after it’s fed through a speaker selector box, a long run of speaker wire, and a volume control.

Thus, what you might not be aware of is that HDMI dynamic headroom outputs from A/V receivers/processors, Blu Ray players, and cable or sat boxes differ dramatically from brand to brand & model to model. It is NOT simply a transfer of 0’s & 1’s from point, “A,” to point, “B,” and that fact is indisputable!

Using my above amplifier analogy, there’s a reason why a Krell 50WPC amplifier, (for example), costs thousands of dollars more than a Denon 50 WPC which can be purchased for 1/10th of the price. There’s a huge difference in the size of the capacitors, toroidal transformers, and power supplies between both units, which in the end relates to the amplifiers’ actual S/N ratio and dynamic headroom the amps can deliver.

Summing up, all that Mr. Boccaccio is stating is that if you start off with a device
that has a higher HDMI dynamic range output, the higher the chance for a successful installation.

Not only is this not, “Snake Oil,” Mr. Boccaccio is not in the business of selling HDMI cables… So to all of you reading his article who believe that he’s making these claims for his own financial benefit, you are seriously mistaken.

Lastly, I was the one who asked Noel Lee how he can possibly justify selling $2K HDMI cables whereas they do not don’t even meet 1.3a standards and his specs are unfounded because they don’t exist. You can read his reply to me in either CE Pro’s last printed issue or search engine on this site, or you can see him physically field the question like a politician on You Tube.  Thus, I too realize the amount of bullsh*t that plagues our industry, but in defense of Jeff Boccaccio, I’m personally assuring all readers that he is telling the absolute truth.

Believe it or not,

Reading on another site, someone explained what was actually said in this article.  I think the problem with the article is it sufferes from lack of information.  It is an executive overview, not a CE Pro article.

Here is my understanding of what he was trying to say in the article:

He is not saying to use EXPENSIVE cables, he is saying to use GOOD cables.

We all know specs have a range to them, so a capacitance spec may be (pulled these numbers out my butt) between 10 and 100 picofarads.  Once you cross teh 100 picofarad line (again, number pulled out of my butt), you get signal degridation and other sucky things.

If you start with a cable sitting at 98 picofarads, you are already almost out of spec. If you start with a cable sitting at 50 picofarads, you have some headroom before you go out of spec. Do you need a cable sitting at 10 picofarads? Most likely not, and that would be both good AND expensive. But you can get cheap cables which are still in the middle range of the spec, and that would make these cabled good.

That is what the article is trying to say (AFAIK), it just fails miserably at saying it.

@ CybrSage:

You get it!

Regarding the original article, (even though it’s as clear as day to me), anyone who has attended one of Jeff’s seminars would clearly see that this article was edited down big time by someone at CE Pro. Thus, the fault/lack of info does not lay upon the author, it lays with an editor who only allotted, “X,” amount of space.

For lack of better words, the space allotted by the editor did not have enough dynamic range to allow the author to successfully communicate all of his information from point, “A,” to point, “B.” 

Imagine that…

http://www.audioholics.com/education/cables/long-hdmi-cable-bench-tests long HDMI cables have already been tested, if you have problems look for a powered HDMI option.

The article has been edited down because it was pulled from the print edition of CE Pro.

The point that I believe Jeff is making is that there are many variables in the signal chain of an A/V system and as a consumer or installer you need to be aware of those variables by over compensating in other areas to ensure reliable signal integrity.