Question on the different types of video cables

[Jack]

This has puzzled me for some time.  There are all sorts of different types of cables for hooking up your home audio/video equipment:  coax cable, rca cables, component video, S video, HDMI, coax audio, optical audio, etc.  I know which ones are supposedly best and which are worst, but the way I see it, your TV signal travels for miles through wires, then for dozens of feet through your house on coax cable, but it seems extremely important that the last few feet from the cable box to the TV be run with some fancy cable.  Does the signal somehow change once it leaves the cable box, making it extremely susceptible to anything but the finest cable? 

I mean, if I, and average Joe, were to replace all the RCA cables with component video and S video cables, is there any chance I'd actually notice a difference?

[Mr_Vindictive]

Well, it sort of all depends on the TV you are using and the equipment you are hooking up to the TV.

Composite Cables (AKA RCA Cables) - These are your standard Red, Yellow, and White cables.  If you have a standard, non-HD TV then this is what you have probably been using for quite some time now.  They are good enough, and the picture is much better than that of just standard coax cable.

S-Video - This is the step up from RCA cables.  The way that S-Video works is that you still have to leave your RCA audio cables plugged in along with the S-Video cable.  S-Video ONLY transfers video.  You'll get a crisper picture than what you would with standard RCA cables.  If S-Video is an option, then I recommend using it over RCA.

Component - Component was the first of the HD options that come out.  An SDTV will generally not have component inputs.  You'll see them on EDTVs and HDTVs.  Each color (red, blue, green, etc) are split up into their own cables so each cable is dedicated to the one color.  If you have an EDTV, then I recommend using this option if your DVD player supports it.  If you have an HDTV that doesn't have HDMI, then I recommend it in that situation as well.

HDMI - HDMI, to me, is sort of the holy grail of system cables.  It's a small cable that delivers crystal clear picture (up to 1080p) and audio all in the same cable.  It reduces all of the clutter you have with every other option and if your TV can handle it, it gives you the best picture possible.  I have a 22" HDTV in my bedroom with my XBOX360 hooked up to it via HDMI.  It's truly amazing just how simple and neat everything is with this option.  If you do have an HDTV with HDMI and a device that has an HDMI output then there is no question, use it!

[AndyC]

Composite, the yellow RCA plug, combines luminance and chrominance signals (the B&W picture and the colours) into one signal, just like analog TV broadcasting but without converting that to a radio signal. The combined signal is then split apart by the TV's comb filter into luminance and chrominance. Each conversion comes with a small loss of quality.

S-Video keeps luminance and chominance separate, retaining picture quality.

Component has plugs for red, green and blue, and usually one for synchronization. It works a bit like a computer's VGA connector.

All of these require separate audio cables, either analog RCA, digital RCA or fibre.

HDMI carries a digital signal directly (video, audio, the lot), without any analog conversion or even data compression. No loss of quality whatsoever between video source and TV.

Personally, I use S-Video at home. It's noticeably sharper than composite, and sharp enough that I haven't bothered to try hooking up component from the DVD (which would mess up my switching arrangements anyway). If you have a setup like mine, with a satellite, DVD, receiver and VCR, component video doesn't offer enough benefit over S-Video to be worth having one oddball component (two, counting the VCR's composite). It adds a couple of unnecessary steps to switch the video source on the TV as well as on the receiver.

I have no reason to try HDMI yet, but it would, at the very least, simplify the cabling.