Yikes. I am
so going to regret getting involved in a potentially neo-religious subject like "high-end" HDMI cables. Oh well...
As everyone else has said, you will either see grotesque artifacts like sparkles (bad pixels), freezes, and dropped-frames OR the picture will be identical for any HDMI cable of reasonable length. Different HDMI cables will not create subtle, quasi-subjective refinements like better detail or black levels.
Speaking both as a computer engineer who is currently studying the HDMI specs (I've written protocol analyzer software for high-speed serial buses like USB)
and as a nutty audiophile who uses "high-end" speaker wire from Transparent, I can state without reservation that all HDMI cables which have passed HDMI certification and can legally display the HDMI Licensing logo will not affect picture quality regardless of price. I am dismayed that nearly every cable company (including Transparent) has jumped on the "our HDMI is best" snake-oil bandwagon. HDMI cables are just as boring as USB and FireWire cables.
The only qualifiers I must add concern A) longer cables where adequate shielding might eliminate the need for a repeater and B) new HDMI standards (specifically 1.3) which support features demanding more data flow (such as 12-bpp color and uncompressed, multi-channel audio).
There are only two types of HDMI cable defined in the latest specs: "Category 1" cables supports data rates up to 75 MHz while "Category 2" cables support up to 340 MHz. The 75 MHz data-rate supports 1080i HDTV with compressed audio. I suspect "Category 1" cables also support 1080p without audio, but I haven't run the numbers. To use all the features of 1.3 spec, "Category 2" cables must be used.
Unlike USB, there is no maximum cable length defined in the HDMI specs, but physics dictates that longer cables can't support faster data rates. So I suspect "Category 2" cables will always be less than 15 to 20 feet.
I ran two 36-foot lengths of
Liberty HDMI cables from my cabinets to my Panny plasma for $140 per cable ($3.89 US per foot). These cables are very well made, are CL2 rated for in-wall use, and supposedly support up to 1080p at up to 50 feet (which I find astounding). Since my older Panny only supports up to 1080i, I've not had a chance to test the higher data rate myself. Regardless, my dual 36-foot runs have been flawless at 1080i with all HDMI sources I've used. These include a RadioShack OTA HD tuner, two el-cheapo $80 upscaling DVD players, and a Sony BDP-300 BlueRay player.
