Home Automation

Levi Pearson levi at cold.org
Tue Feb 20 11:23:37 MST 2007

"Dan Stovall" <dbstovall at gmail.com> writes:
> I have read in several places recently that there is no difference
> between expensive HDMI cabels and the cheaper kinds.  Most things I
> have read state that since the signal is digital and won't degrade,
> either the cable works or it is broken.  It won't matter if you by
> $100 Monster cables or $20 cables from monoprice.

This is probably true for most installations.  It may even be true in
general, if the impedance tolerances are similar between the cheap and
expensive cables.  But just because the signal is digital doesn't mean
it doesn't degrade.  AFAIK, there is no error correction built into
the transmission protocol, and it's essentially transmitting
full-frame video data rather than MPEG, so a single bit error on the
wire will probably end up as a bad R, G, or B value on one pixel for
one frame.  I've seen this degradation described as 'sparkles'.  I
assume that if the signal is bad enough that it can't properly detect
transitions accurately, it just shuts down.  

Anyway, it's (usually) copper wire, with no error correction, so cable
quality does matter.  As usual, there is not necessarily a fixed
correlation between quality and price, but as your cable length grows,
the necessity of getting a quality cable increases.


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