[Johnny Bax]

The other day I brought home my new Marantz SR7400 receiver, which has video upconversion, or what some call "transcoding". My plan was to connect my DVD player and directv receiver directly to the SR7400 inputs, then output one component cable out to my projector.


Problem was, I only had one component cable, the one that is now being used as the output from the SR7400 going back to my projector. Previously, it was used to directly connect the DVD player with the pj.


Since I didn't have another component cable laying around, I decided to try a set of monster cables I had in the closet from a previous installation. This was a three wire set, with a yellow composite video, left audio and right audio. I used this ad-hoc cable to connect the DVD player to the SR7400.


The resulting degradation in video quality when playing a DVD was horrible. Colors were limp, the picture quality was not crisp and the overall picture was lifeless. So, I went back to running each component to the pj directly and skipped the transcoding for now until I can get another good set of component cables.


What is the difference between component video cables and composite video cables? They both have RCA type connections, so I assume it's in the shielding? I understand that the component cables separate the RGB signal into three cables, but I'm not quite sure why the three cables I used wouldn't function in the same way.


Thanks for helping me understand this.

 

[tvtech1]

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What is the difference between component video cables and composite video cables?

Nothing, both require 75 Ohm coax.

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They both have RCA type connections, so I assume it's in the shielding?

All coax cables are sheilded.

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I understand that the component cables separate the RGB signal into three cables, but I'm not quite sure why the three cables I used wouldn't function in the same way.

Cables don't do anything but carry a signal. Component consists of a luminence signal and 2 colour difference signals.

The 'monster' cable that you used is probably very poorly made, because, even at short lengths, the 2 audio cables should have been able to carry the colouir difference signals.

Just get RG59 and make your own.

 

[_Arklyte_]

What tvtech1 said. Both work just fine.


I went to radio shack a few weeks ago to pick up some 12' cables and the salesman asked me what it was for. Well, as I grabbed the $10.00 pack of composite cables, I told him I needed to move my HD tuner. He then told me "Those won't work"


Really? i said. Now I'm interested in the tripe he was going to unload so I asked why not.


He said because they won't carry the signal. They will only carry 2 audio signals and 1 video. It will cancel out the required video signals. You need these "component" cables from monster.


I told him he was full of crap, please stop cheating your customers and learn your job. The only friggin difference between these cables and the $60 monster component cables. aside from the obvious price gouge is the pretty little color bands on the RCA jacks.

 

[plasmamaniac]

All picture sources are comprised of RED, GREEN and BLUE COLORS. Cables can be rated as delivering these separate color sources as follows with Number 1 being the best delivery source:

(1) DVI/HDMI - Digital Visual Interface

(2) Component - Red, Green and Blue Separate in separate component signals.

(3) S-Video - RED, Green and Blue more separated with algorithms to separate RGB

(4) Composite Video - Oldest version of video cable which has all colors, Red, Green and Blue mixed. Separation of the colors is not perfect therefore

the resulting picture is far from being close to the source.

 

[Brown Radagast]

I say some A/V cable techie needs to chime in with the specs for composite cable & component cables to let us know once and for all if there is a difference?


My eyes say that there isn't - I too have used composite cables to connect my DVD player to my PJ via the component jacks, as well as my PS2 via the component adapter for that.


Quality of construction for cables is another issue though...

 

[barrister]

Well, I used to think the cables were the same, but my own experience proved that it is not the case. In January I purchased a new Mitsubishi 65613. I immediately dug into my box of home theater cables, and hooked up my DVD player to the component video inputs on the Mitsubishi. NO PICTURE. I tried various other cables of different levels of quality (including Monster cable) STILL NO PICTURE.


Frustrated with the high price of component video cables at Rat Shack or elsewhere, I ordered a 6 foot set of 5 lead (component plus audio L+R) at Showmecables for $14.71. Upon receiving the cables a week later, I plugged in the DVD player, and voila, PICTURE.


There must be something to the bandwidth of component video cables and the ability of the Mitsubishi to receive the signal through the component video inputs, no?

 

[tvtech1]

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Cables can be rated as delivering these separate color sources as follows with Number 1 being the best delivery source:

Except component, Y/C and composite don't carry RG&B at all. As explained above, component carries 2 colour difference signals and a luminence signal.

 

[plasmamaniac]

tvtech1, I beg to differ with you. The Yellow video in composite carries all of the 3 colors, Red, Green and Blue but has to be separated with a process that is not perfect. It is old technology. So they came out with S-Video when color TV came out to increase the color resolution. Then component came out which separates the 3 colors in a more efficient process so the resulting process and output is better. Now we have DVI which keeps the 3 colors Red, Green and Blue in a digital mode (HDMI is now added which adds audio to the DVI process). If your component port is not working or you don't have the component cables all the way in, then you will have problems. I just sent back a wireless device because it didn't process component signals very well. All I got was a blue screen. The Samsung SIR-TS160 STB was notorious for having a BAD DVI port which is why I use component. I use DVI output from my HD TIVO because it works. The best is DVI(HDMI), next is component (make sure all connections are plugged all the way in), S-Video and last and worse is composite( one yellow for video, red and white for audio). Good Luck.

 

[tvtech1]

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The Yellow video in composite carries all of the 3 colors,

It carries a signal that includes a modulated subcarrier, the phase relationship of the subcarrier to burst represents the colour difference signals, U and V.

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So they came out with S-Video when color TV came out to increase the color resolution.

Composite was 'invented' to maintain compatability with monochrome sets.

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Then component came out which separates the 3 colors in a more efficient process so the resulting process and output is better

Component carries a luminence signal and 2 colour difference signals, not RG & B.

 

[plasmamaniac]

You know what we are talking about so why get so technical. If you don't think that the process for decoding component signals is not better than composite than I don't understand where you're coming from. You obviously know that DVI is better than component if everything is working properly and according to specsand component is superior to S-Video. A BAD DVI port or a BAD COMPONENT PORT will cause problems that most people think are the result of a bad video connection.

 

[tvtech1]

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If you don't think that the process for decoding component signals is not better than composite than I don't understand where you're coming from.

Why do you insist on putting words in my mouth? if you don't understand something, just ask....

 

[plasmamaniac]

Component carries a luminence signal and 2 colour difference signals, not RG & B. It carries R,G and B with hidden luminance signal which it decodes but you know the less decoding that has to be done then the better signal and the better reception. I hope that you don't recommend composite video cables for a HD plasma or other HD display because if you do then you do not know what you are doing.

 

[tvtech1]

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Component carries a luminence signal and 2 colour difference signals, not RG & B.

Very good, I've posted this 2 or 3 times in this very thread.

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It carries R,G and B with hidden luminance signal

The R G & B signals are weighted and summed together to produce the luminence signal.

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I hope that you don't recommend composite video cables for a HD plasma or other HD display because if you do then you do not know what you are doing.

Based on that comment, it's clear that you don't really know what you're talking about. Read this thread for a clue.

Cables that are capable of carrying a composite signal are perfectly capable of carrying a component signal.

 

[Brown Radagast]

I think we all have at least a basic understanding of the different types of signals.


What I'm asking is if there is a difference in the bandwidth between a composite (yellow) cable vs. the component (red/green/blue) cables.


An example would be if I were to walk into Radio Shack today, went to the cables, and saw a composite 12' cable for $5 (***MSRP***), as well as a component set of cables - 12' for $20 (***MSRP***) - they SEEM to have the same cable wrapping material and similar connectors, but are their bandwidth capabilities the same? I would think yes, because provided the copper is the same gauge, then the bandwidth should be the same, unless there's other construction materials that are used and are standard to component cable construction that I don't know about?


Quality would be a different matter. I mean, if a person made a DIY set of components using RG6 or RG59 cable, the bandwidth capacity would be greater than those above-mentioned cables, right?

 

[Rop]

Brown hits the hammer on its head: It depends on the bandwidth of the individual cables in a set of composite cables...


There's no problem with the yellow (video) one, it is coax and it'll very likely carry component video just fine. The problem is the other two, red and white. They are meant for audio and may well be just plain audio-grade shielded wire. Not coax, as in video-capable coax. If this is audio wire their bandwidth would be atrocious (audio = 20 KHz, component video = 50 - 75 MHz, a factor of 2500x difference in bandwidth).


Now, it may well be that some manufacturers use coax (RG59 or some such) for all three leads of a composite cable set. If so, it'll work just fine for component. I have a cheap composite set at home where that is definitely not the case. The video lead is made of (thick) RG59, the audio leads are much thinner.


In short, my $0.01: "It depends"...


-Rob-

 

[tvtech1]

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Brown hits the hammer on its head:

Nail, you hit the nail on its head

 

[plasmamaniac]

Johnny Bax, I am a certified ISF calibrator. We spent many hours talking about cabling in the class. The oldest version is composite which was used for black and white TVs back in the good old days. Then color came out and it was merged into the composite cable. Then people wanted better color so S-Video was developed which separated the color signals better than composite. Then component was developed. Three cables together, Red, Green and Blue with the luminance added in one of the 3 cables. Therefore you get better color because they are separate and don't have to be separated by a formula which is not 100% correct. It therefore gives you better color. It has nothing to do with the copper or shielding or the connectors. It is the type of signal that has to be processed. That's why your HD displays have component and not an even better cable process called DVI which is a digital signal never having to be converted to analog and then back to digital for a display device such as a plasma. Therefore you lose nothing because there is no need for conversion. Monster Cables are great cables but they are overpriced. Acoustic Research at Best Buy are about half of the price of Monster Cables and I have demonstrated this to many people in an A/B comparison test. Composite cables do not carry component signals. All 3 colors are combined together and then later separated by a process which is not very exact which results in less than perfect colors. Component cables keep the colors separate which results in better color. DVI can be even better. Pacific cables have good prices also. Composite is the worst signal that exists. That's why all your DVD players have component connections. They want you to see to best picture possible which makes their DVD player look good. They never recommend composite connections even though they throw it in if you think you might want it.

 

[tvtech1]

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Johnny Bax, I am a certified ISF calibrator. We spent many hours talking about cabling in the class. The oldest version is composite which was used for black and white TVs back in the good old days

Composite video was developed for use with COLOUR tv's not monochrome.

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Then people wanted better color so S-Video was developed which separated the color signals better than composite.

S video is the same NTSC signal as composite, without summing the luma and chroma, it has existed since composite has.

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Then component was developed. Three cables together, Red, Green and Blue with the luminance added in one of the 3 cables.

The first type of colour signal 'developed' was RGB. Summing RG&B and syncs produces a luminence signal, compatable with monochrome TV sets. Two colour difference signals are also generated from the RG&B signals, called R-Y and B-Y, these three signals comprise a component signal. It is not the same as an RGB signal.

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Composite cables do not carry component signals.

Any 75 Ohm coax cable will carry a composite, component or s-video signal.

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Component cables keep the colors separate which results in better color

No they don't, as explained above.

 

[plasmamaniac]

Why then are there 3 different cables in component cable? To keep the colors separate.

 

[tvtech1]

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Originally posted by plasmamaniac Why then are there 3 different cables in component cable? To keep the colors separate.

Then why do they combine all 3 colours (called the Y, or luminence signal) onto one cable, and then create 2 colour difference signals for the other 2 cables.

I am trying to explain the difference between RGB and component to you, since you don't seem to know.