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So, If I can receive an HD signal through coaxial cable from Comcast. Why don’t TVs just accept that? Why is there a requirement to use HDMI cables from the cable box to the TV? Wouldn’t it be easier just to continue to use cable?
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What gives? Fry’s (and other similar stores) want over $100 bucks for HDMI cables. I can easily find similar rated cables on the Internet for less than $10. I know the Internet is usually a cheaper place to find stuff… but 90+% less?
Those $100 HDMI cables are (for the most part) for suckers. There’s a new one born everyday, you haven’t heard?
That’s what I heard; but I just wanted to get more confirmation on that. That’s amazing. I could see even half price on the internet, but is there any other product that has that much price disparity for the same product?
E3
Look at anything sold to audiophiles, like speaker cables. There are many charlatans out there that are willing to exploit the ignorant.
There’s no technical reason I’m aware of. So long as the TV has an ATSC tuner, it can receive HD signals via coax. The kink is in the cable box. It would need to contain an HD “modulator” to turn the HD signal it’s received, tuned and decoded back into a signal suitable for carrying on a coax cable.
Said modulator would bring three unwelcome things to the party: Extra cost in the cable box, one more thing for the cable company to support and troubleshoot, and signal degradation caused by running the TV signal through another cycle of modulation into a transmittable form. Also, the TV networks, the cable company and the FCC all take a fairly dim view of people re-broadcasting programming, and the modulation process is the first step in transmitting signals. Even if you don’t try to transmit it, signal can leak out and cause localized interference in your neighborhood.
As for cable prices, you’re looking in the wrong bins at Fry’s. I got my HDMI cables at Fry’s for under ten bucks each. Avoid anything with the word “Monster” in the name. Amazon also sells HDMI cables at a good price, and I’ve heard nothing but great things about Monoprice.
(1) Some do. Look for a TV with a QAM tuner. It will happily tune to digital cable broadcasts, including HD, as long as they aren’t encrypted. Even if they are encrypted, if the set has Cable Card capability and your provider is willing to give you a Cable Card, you’ll be able to watch those channels.
(2) Marketing BS plain and simple. There’s no reason an HDMI cable should cost more than $10. It’s a digital signal so phase-inductance matched prehistoric nitrogen isolation doesn’t do a damn thing (not that it does for analog either).
But there’s the rub. I think encryption is the main point of HDMI (pretty sure some DVI can do it too). You positively need HDMI for Blu-Ray for this very reason (HDCP compliance). If your cable company wants to stop you from recording shows to force you to pay for their own DVR service this is what they would do.
Also depends on how your cable company is compressing their signal. If they are using a standard MPEG compression then fine but who knows if they decide to do some proprietary compression? It is far easier for TV manufacturers to just design the TV as the final output and leave the fancy stuff to other components. Once decompressed I do not think a coax cable can carry the signal. You need HDMI/DVI to carry that kind of bandwidth and your TV need not figure out anything. If something changes down the road you only need a new tuner instead of a whole new TV.
Also HDMI has a channel that allows for other features such as remote control of other components. So if you tell your cable box to auto shut-off the TV at midnight because you expect to fall asleep the cabel box can tell the TV to do that (I know some TVs have this feature…just an example and in this case the cable box could tell any TV run by HDMI to shut off).
Broadcasters use SDI, which can carry uncompressed digital video over a single piece of coax. It’s simple, cheap, and what everyone could be using if it wasn’t for Hollywood’s hostile attitude towards their customers and their political influence.
I bought my parents an HDMI cable at Fry’s. $8 in the computer components section of the store.
Of course, I could have picked one up for a minimum of $50 in the TV section.
HDMI is just a digital connection, like ethernet or SDI or DVI. Devices can choose what to send over that link.
HDCP and signal encryption is a handshake between two devices connected by a digital connection (HDMI and DVI being the only ones with the requisite bandwidth for HD). It is not a property of HDMI; HDMI is just a carrier device for digital streams.
This is a good thing – if the compression or encryption method changes, it makes sense to change out an intermediate component instead of the display. Which I think is what you meant, just clarifying. 
HDMI also simplifies the audio chain – previous HD hookups might use a component cable (YPBPR) + some sort of digital audio interface like TOSLINK or coax audio. That said, most consumers with HTRs would probably do cable box->HDMI->HTR then split that to HDMI to the display sans audio, and plain old copper to speakers.
Pretty good article (well researched) about HDMI cables is here:
I wasn’t aware there was that much to it. Makes interesting reading.
M
Admittedly I am no expert on the technology and part of me wants to think you are right. Presumably the handshake could occur over any connection. But apparently it doesn’t. Blu-Ray I think demands HDMI (maybe DVI could do it too since near as I can tell they both achieve the same thing and a simple, cheap adapter can convert one to the other). But I have seen many reviews of LCD panels that bemoan a lack of an HDMI connection saying you cannot plug in your Blu-Ray or PS3 or what have you and expect it to work.
Yep…that’s what I meant.
TV’s are drifting more to a display format. That is they are just the output. All the fiddly crap is dealt with elsewhere and they just draw the end result.
With computers and DVDs and Blu-Ray and console games and cable (many providers) vs satellite vs broadcast it just gets too hard to plop everything in one set. It’d be nice if there were worldwide standards everyone agreed to but obviously that does not happen.
So, far easier and cheaper for the manufacturer to make a display and leave the tuner/decoding/decompressing crud to some outside unit. Then if a consumer moves and they switch from, say, cable to satellite they only need buy a new, relatively cheaper, external box to deal with it and their $2000 plasma display need not go in the garbage.
Well, I did say that the handshake requires a digital connection, and DVI and HDMI are the only digital connections available. All the rest – S-Video, Component, etc (ignoring that some TVs have USB ports) – are analog connections.
I think our disconnect may come from the signal versus the medium that carries it.
Is there any reason a digital signal cannot be carried on a coax cable? Or two dixie cups and a string? 
No, but no television manufacturer tries to decode digital signals on their analog connections. It could certainly be done – think of how old modems work over POTS lines – but nobody does. You’d need to change televisions to detect that there’s a digital signal coming over, say, the three component video connectors, and the television circuitry would need to decode the signal instead of sending straight to the display. I also suspect the bandwidth would not be high enough for digital television, but I’m not an EE.