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Digital Coax

#1
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6/11/05 at 8:35am
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How are Digital Coax, Composite cable and Component cable different?
Digital Coax can be used for Composite video but not Component?
How else are they interchangeable?
Are they all Coaxial cable?
Thanks,
James
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#2
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6/11/05 at 12:53pm
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Quote:
Are they all Coaxial cable?

Yes.

However, there are caveats. Ignoring for a moment the quality of the cable, (I recommend Canare/Belden pro-grade cable for the most demanding applications esp. video, and this is not at all unreasonably priced) Video applications and digital coax require 75ohm cable. Analog audio does not need to be any specific impedance. So as long as you have a 75ohm cable, you can use that for anything. If you are using such a cable in a really demanding application, say HD video, make sure you are using a quality cable.

Analog audio cables may well be 75ohm as well, but unless you know that they are 75ohm cables, don't use them for video as you may get ghosting if they aren't, and don't use them for digital coax transmission as you may get dropouts.

So a good 75ohm cable can be used for anything, basically. Analog audio does not demand 75ohm, so audio cables may be some other impedance, so you shouldn't use analog audio cables for other tasks, unless you know that they are indeed 75ohm coax.

Hope that helps!

Please see my: Advanced Guide to Source Options

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#3
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6/11/05 at 1:47pm
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Yes, that does help. I didn't NEED to know as I have all my cables, but I like to know what and why I have it.
Thanks
James
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#4
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4/22/09 at 3:26pm
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Re: Digital Coax

Can digital coax be used for 1080p video from the receiver to the tv, for example?

D.
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#5
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4/22/09 at 4:10pm
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Re: Digital Coax

Yes, but exceedingly few video devices output 1080p over component, and many TVs won't accept 1080p over component. Most of the time you need HDMI for 1080p.
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#6
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4/22/09 at 7:29pm
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Re: Digital Coax

I've asked this in a different thread and am taking baby steps in understanding: in a new pre-wired home theater set up, I have what I thought was RBGHV cable but is really 5 strand RGB HI-RES HDTV Digital Coax (HomeChoice from Belden) from the HT closet to the living room wall where the tv will be mounted about 40ft away. Don't know why it was wired this way instead of HDMI. Don't want to open the walls if I don't have to. Can't pull the wire. So the question is: (how) is this guy/company going to be able to deliver a 1080p picture? What will those connections be?

What can you tell me? Thanks.

D.
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#7
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4/22/09 at 9:15pm
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Re: Digital Coax

So basically you have miniature component video cable. It's fine for 1080i/720p as you can just use 3 of the 5 strands to send Y/Pb/Pr component instead of the RGBHV.

1080p, as mentioned before typically you only get it with HDMI. You can do a few things over RGBHV, like computers, xbox 360 output, in 1080p, but generally are limited to 1080i/720p from other sources like cable/satellite boxes, DVRs, Blu-ray players etc.

Can you put any pressure on your contractor to put in HDMI?
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#8
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4/23/09 at 8:13am
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Re: Digital Coax

You may not be able to tell the difference between 1080i/1080p in any case.

Before making any changes, set up your display and a source (e.g. BD player) that can deliver the same picture in both 1080i and 1080p. Check both to determine if you can see a difference (at the distance where you will normally watch) and if you can actually see a difference, decide if that difference is big enough to warrant changing your cables.

And don't forget that the best you will get from some source (satellite services like Dish or StarChoice) is only 1080i.
¡Time is not my master!
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#9
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4/23/09 at 11:08am
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Re: Digital Coax

These are very useful replies. Glad I asked again. Thank you.

D.
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#10
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4/23/09 at 8:13pm
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Re: Digital Coax

Quote:
if you can actually see a difference, decide if that difference is big enough to warrant changing your cables.

Even if you can't tell a difference, I would try to get the guy to run HDMI for me if 1080p was promised, because there is some non-zero possibility that some years from now studios might implement the "image constraint token" on some discs, which would limit output to 480p over component, requiring HDMI for anything higher. That would suck. HDMI is the right solution long-term, I would feel ripped off if a HT contractor ran only component these days without mentioning the limitations. (Leave the component in there, it's good to have both options.)
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