HDMI cable quality, specs, and noise...

HDMI 1.3 is the first version of the HDMI spec that requires different cables to take advantage of the new features.

New features in HDMI 1.3 include

• Support for HD Audio specs including Dolby Digital Plus, Dolby TrueHD, and DTS-HD
• Higher bandwidth - although 1.3 is faster, the extra bandwidth really isn't necessary for equipment currently on the market. Future HD displays with resolutions higher than 1080p could make use of the extra bandwidth.
• Deep Color support - now supports more colors than the human eye can comprehend
• Lip Sync - helps keep audio and video synchronized.
  

That being said, you still need an input and output device that supports those new features as well.

I believe the "com link" you are referring to is known as HDMI-CEC which stands for Consumer Electronics Control. This lets a device such as an AVR control the TV without the need for a universal remote. The HDMI-CEC spec has been part of HDMI since the beginning but was never taken advantage of until 1.3 hit the market. So I don't think you need a 1.3 cable to use the CEC features. I haven't used a CEC compatible TV though so I'm can't say for certain.

I'm not sure what the iron ferrite cores are supposed to do, maybe it has something to do with keeping the electrons in the cable clean. I did a quick search online and didn't come up with much of anything about it. I wouldn't worry about it.

As far as cable quality goes, since the signal is digital it's not as important to get a high end cable as it was for analog devices.

Thank you kindly for your highly developed response.

As background- we are a distributor of some of the more reputable brand of home electronics you see in the recreational vehicles, yachts, and modular home industries.

Your response leaves no questions in my mind- save for why the cheaper cable we bench tested ("1.1 spec" I believe it was called by someone in the shop) failed to enable Sony's "Bravia_Sync" or the Samsung's version of the same thing either. These offer auto input selection and auto-turn on of connected devices for instance. Testing confirmed any 1.3 allowed the feature to run- but the cheap cable was a no-go. This "cheap" cable is an "included" accessory in an off-brand DVD device we got into selling somehow or another. The failure to "link up" must be tied to non-1.3 cable usage...would you concur? Any thoughts or comments?

Thanks again so much!

James

After some further reading it looks like HDMI-CEC might have first came up in the HDMI 1.2 spec but before HDMI 1.3 there weren't special cables for HDMI 1.2

With HDMI 1.3 they added a few new CEC features including timer and audio commands.

Technically all CEC devices are supposed to work together using generic commands but the spec also gives the manufacturer the option to use custom CEC commands.

I have read most CEs use the custom CEC commands just so their equipment is "proprietary" and the consumer is more likely to buy other equipment from the same manufacturer if it will work better together.

I'm not really sure if the custom CEC commands were in the spec before 1.3, but if you are testing it out on an older cable that doesn't work and a newer cable that does work, it looks like that must be the answer.