Are RCA cables and Component cables the same?

September 14, 2006 5:34 AM

Can one use RCA cables (red/white/yellow) in component jacks (red/blue/green)? I understand that the jacks carry much different data/signal/whatever, but I was told that there is no need to buy (very) pricey component cables...you can actually just hook up good quality red/white/yellow RCA cables to the component jacks for the same purpose.

My backstory: for some reason, I am a complete AV dolt. I don't get it and can't wrap my head around wiring and hooking up my new digital video box, home entertainment receiver, and new LCD tv with all sorts of in/outputs.

So, I went to radioshack (ugh...hate that place, but I was in need of a quick fix to get this all hooked up) and the guy asked if I had component outputs, and that hooking these up with component wires (the three red/blue/green wires) would give me the best possible picture. So I bought some $45 package of Monster component cables (knowing full well that this guy was probably upselling me and raking me over the coals...but not understanding enough to be able to know for sure...hate that feeling).

I got home and my friend who was helping me set everything up mentioned to me that it was merely the inputs that were different; the component jacks were what carried "better" picture data...the cables (within reason) were more or less irrellevant. The cables just carry that signal.

I tested it out...and over the short distance hooked up (about 2'), I noticed no change in picture quality whether the component jacks were connected by dedicated (expensive) component cables or by good quality (but 1/2 or more as pricey) RCA cables.

I found this discussion on Yahoo Answers...but it seems like there if just a lot of back and forth ("yes, they are the same" and "no, they are totally different.").

Should I return these expensive cables and just go with some high quality RCAs in the component jacks? Are dedicated component cables really only marketed for suckers like me?

Thanks!

posted by tpl1212 to technology (17 comments total)

The answer is that it depends what you are doing with them. Regular RCA cables will work fine for regular component signals but if you start trying to stuff an HDTV signal down them, you may well encounter problems. I tried to wire up my home theater using RCA cables for the HDTV pathways (just because I wanted to see a picture without going to the hardware store right then) but the cheap RCA cables simply don't have the bandwidth to carry an HDTV signal.

IE it didn't work.

When I swapped out the RCA cables for decent component cables it worked fine.

However, working in the TV production business, we used standard RCA cables to hook up standard definition component outputs all the time.
posted by unSane at 5:52 AM on September 14, 2006

If you can't see it, why pay for it? At least, that's the common sense answer.

But the question of cables contributing to signal quality has been running for so long in the audiophile world, that I think it has sort of bled over into all areas of A/V. Over such a short run as a 2 foot interconnect, measurable differences in cables such as capacitance, and high frequency roll-off are going to be so minimal as to be entirely theoritical, in my opinion as a former professional broadcast engineer. Gold plating on cable connectors makes no difference if your component outputs are tinned connectors. Cheaper wires may be made of less flexible conductors, so in uses where they are frequently moved or reconnected, higher quality wires with better conductors and strain reliefs may be worth something, but for semi-permanent home connections, even this justification for more expensive cables is hard to make.
posted by paulsc at 5:58 AM on September 14, 2006 [1 favorite]

All of that is true except that in the case of HDTV signals a cheaper cable simply may not work. It's worth a try, but if you get a black screen you may need the more expensive cable.
posted by unSane at 6:02 AM on September 14, 2006

It's becoming a bit ridiculous trying to buy decently-priced audio or video cables at any big box or retail electronics outlet. Especially at Best Buy or Future Shop (the latter being Canadian only) cables are one of the highest-margin products in the entire store. $30 for a 6' USB A-B cable is not unheard of. Wholesale, they are about $3 or less.

Try to find an alternative: a smaller TV or electronics shop, perhaps independantly owned, or an electronics surplus store. I get all my a/v cables from the surplus store now - for the reasons paulsc said above, on a short run you won't see the difference between the $50 cable from RatShack or the $5 one from the discount store.
posted by chuma at 6:05 AM on September 14, 2006

As an addendum, while the new tv is HD-ready, we don't have any HD channels (ie: we're not trying to view an HD signal through RCAS).
posted by tpl1212 at 6:21 AM on September 14, 2006

I tried this with a some random RCA cables and the video was always green or blue or had crazy lines running through it. I never did get component to work. So I dont know if the problem are the cables or the tv/DVD player. Composite works fine.

Maybe someone more knowledgable can help us both. I'm hesitant on spending gobs of money on cables I cant return if this doesnt work.
posted by damn dirty ape at 7:00 AM on September 14, 2006

The answer is: maybe. Depends on the 'quality' of the RCA cables. The real answer is that, for a bunch of complex math reasons, component cables may be manufactured to higher specs than plain old RCA cables. Without going into too much detail, audio and composite video (the yellow one) are more tolerant of cables that don't meet the 75ohm spec. Most red/white/yellow RCA cables are closer to 35-50ohms. HD is considerably higher bandwidth (35mhz vs 10mhz of composite video) and less tolerant of cables that aren't 75ohms.

The most dramatic demonstration is seeing what a signal looks like going through cable that can't handle the bandwidth. You can literally see the signal smearing on a good oscilloscope.

I say "may" because there are so many ways you can be ripped off it's not even funny.

So, spend a few bucks for component cables but not too much.

unSane, those standard RCA cables you're using are probably more accurate than they look.
posted by jdfan at 7:16 AM on September 14, 2006

I hope I'm not too late to help out. I have no affiliation with this company, but Monoprice.com is loaded with TONS of really cheap generic cables at very reasonable prices. I haven't bought anything there myself, but I haven't seen any complaints.

For instance, a 6-foot 3-RCA component video cable is $4.21 for one and there is quantity discount starting at just 2.
Step up to the Premium version for $12.54.

Yeah it's online and you have to wait for it, but at least you're not lining the pockets of Radio Shack or Best Buy (if you don't want to). Think of it this way: it's cheap enough to give away to a friend if you end up not needing it.
posted by Sasquatch at 7:23 AM on September 14, 2006 [1 favorite]

Um, it depends -- do the round metal things on the component cable ports have little nubs on the outside of them? They might be BNC connecters instead of RCA connectors, in which case ... NO, DO NOT TRY TO USE RCA CABLES. You'll likely break the connector. ;)
posted by SpecialK at 7:34 AM on September 14, 2006

the component jacks were what carried "better" picture data...the cables (within reason) were more or less irrellevant. The cables just carry that signal.

Coaxial cables don't just carry the signal. There's a complex interaction between the inner core and outer sheath and the dimensions of each and the material used between them changes their electrical characteristics. The cables can be considered an electronic component that can change the signal.

On the other hand, this is mostly theoretical for short cable runs, so no, you don't really need the expensive cable.
posted by cillit bang at 8:03 AM on September 14, 2006

Sasquatch, that site you link to seems to be low enough priced that...that one might as well buy "dedicated" component cables and forgoe all this discussion...thanks for the link!
posted by tpl1212 at 8:33 AM on September 14, 2006

damn dirty ape, there’s more than one standard for component video. A DVD player outputting RGB to a TV expecting YPbPr input (or vice versa) can cause the type of interference you describe. The factory-default component output setting of the Sony Playstation 2 was incompatible with my Sony TV, for example.
posted by hilker at 9:16 AM on September 14, 2006

Cables for Less is another great place to buy cables. When I bought an HDTV i purchased two HDMI and three component cables from them for about $50 total, compared to $99 for a single HDMI at the store. They are also very helpful over the phone.
posted by bcnarc at 10:49 AM on September 14, 2006

Okay, here's the deal: Audio cables have an impedance of 35-50 937;. Component video cables ought to have a 75 937; impedance. So at least in theory the cables are different.

What an impedance mismatch will do to you is cause the signal to reflect inside the wire, which in audio would cause either ghosting or horizontal lines depending on how far it's bouncing. If the cable's short enough it may not matter at all.

Basically, however, if you can't see the difference, there is no difference that matters.

Also you can buy cheap component cables, you just have to look around. This was important for me since I was doing a 25' run of it, at which lenght Monster or other exploitative brand-name cables are like $150. Frys/Outpost.com had some pretty reasonable prices.
posted by aubilenon at 11:12 AM on September 14, 2006

http://www.cablewholesale.com/ seemed to have cheap cables too, but I've never ordered from them.
posted by RikiTikiTavi at 1:24 PM on September 14, 2006

Component Video Cables: The Definitive Guide
posted by Neiltupper at 2:00 PM on September 14, 2006

hey, my unicode got munged. (Those are Ohm signs)
posted by aubilenon at 2:38 PM on September 14, 2006