HDMI Cable comparisons

There is a well known problem of interface jitter from transmitting the clock signal along with the data. I would agree that in the scheme of things this form of distortion is usally pretty small nowadays (compared to other problems like speaker distortion) but nevertheless it provides an example of why a digital cable might make a difference.

The jitter issue you are referring to is completely independent of the cable and symptomatic of the chosen bit stream framing format (tying the video and audio signals together in a certain way). Changing cables from a cheaper brand to more expensive brand has no effect on the jitter issue you are referring to in your post. Given the same exact lengths of cable and gauge, a $20 cable and a $2000 cable have the same exact jitter issues...

Likewise, the jitter levels introduced are imperceptible. Except by people with overactive imaginations, but they are hearing their imagination, not jitter... :D

Shadorne,

In other words, what you are referring to is a product of HDMI in general (though no one has scientifically proven they can actually hear that small a level of jitter). It is an issue with the HDMI format itself, independent of cabling.

Here is an older thread, but it has good technical info on jitter and HDMI. I'll post a link to page 3 which contains the most relevant info, but it is a great thread overall for info on jitter in general.

http://www.avsforum.com/avs-vb/showthread.php?t=908665&page=3

Jkalman,

Thanks for the links. It seems to corroborate my statement that interface jitter is a well known problem when devices are synchronized using a clock signal - or am I missing something? The way I see it, a long run of HDMI cable might behave differently from a short run. I agree that good quality equipment should effectively handle the interface jitter in both cases to the point that either cable is indistinguishable to the ear in double blind tests. I was only trying to point out that in some cases of borderline equipment performance then an audible difference "might" occur. I realize some authors have suggested that as much as 20 ns is necessary for jitter to become audible and since there are infinite forms of jitter the debate may never be resolved, however, it is easy to show that certain forms of signal correlated jitter will indeed rise above the noise floor at 100 psec on very high quality gear (whether this is audible or not - this simple fact has a tendency to cause concern because S/N is such a standard specification in our industry and modern electronics has incredible S/N performance).

I was only trying to point out that in some cases of borderline equipment performance then an audible difference "might" occur.

Not in the context of $100+ (or even $50+) HDMI cables vs. $20 HDMI cables of the same length and gauge. If the cables have the same gauge and length, they will behave the same... You don't have to pay excessive amounts of money to get the same gauge and length as some companies that charge $200+. The jitter is going to be the same amount in both cables, yet you are insinuating someone should pay more for one digital than the other because it "might" be different. It isn't different... So don't pay more for a cable to get an imaginary benefit.

That thread I pointed out to you also mentions that jitter is eliminated at several places in the receiving end before the signal is turned into analog (though there was some questioning of buffer size needed to prevent overrunning the buffer). Plus there were links to pages that provide DBTs with jitter. It really is a non-issue now a days at the levels these preprocessing units function at...