Some basic questions on cables (1 Viewer)

[Geoff I]

I think I understand this: for component video, I need three coaxial cables measured at 75 OHMs each. I've read that the Radio Shack gold series cables (the typical ryw rca ones, not the component ones) would work for this, is that true? Does Radio Shack also sell decent optical cables? And I've read that people use 75 OHM cables for subs, but would a 5? OHM audio cable work?

 

[John Coleman]

Geoff,
I work for a premium audio and video cable company, Cobalt Cable, and I think that I might be able to help answer your questions. I will answer them one at a time.
Component Cables:
Yes, you will need three 75-ohm video cables for use with this application. I have used Radio Shack's Gold cables, and their price/performance ratio is usually very good. However, a component video connection is typically a high bandwidth application, and quality cables will make a difference (especially with a good display and/or DVD player).
Optical Cables:
As far as optical cables go, I have never used the Radio Shack variety. For optical cables, I will usually go with as robust cable as I can find. The fragility of optical cables frightens me somewhat, so I will usually look for cables with as sturdy connectors as possible.
Subwoofer Cables:
There is a lot of debate as to the value of high quality cables in partial channel (especially LFE) situations. Any audio cable will probably do the job for you (I have even seen people have pretty good performance using an RG-6 coax cable with F to RCA adapters on the ends). I typically use at least audio-interconnect grade connections for my subwoofers, though.
You have got a few things going on here, and I have probably just scratched the surface of your questions. If you would like any more information or advice, please feel free to e-mail me privately. I hope that helped.
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[Bob McElfresh]

John: When I heard you work for a "premium" cable company, I was getting worried. But your advice was dead-on what I feel/know to be true. You have my respect and I look forward to hearing your expert advice here at HTF.
Geoff: A few months ago someone tried a set of the L/R/Video cables from Radio Shack and found them to work fine as a component video set. (This make sense that they would simply create a bundle of 3 identical wires and just slap different -color RCA plugs on the end).
So for a short (sub 6 feet) run to a Tube-type TV, one of these sets should work fine.
But what John started to mention was that this inexpensive cable will not works as well if:
- Your TV gets larger than say a 35" tube
- Your run-length grows longer than say 6 feet
- You try and shove not component video, but Progressive/HD signals down the wire.
So how big is your TV, how long is the run, and are you sending progressive signals?
Sub Cable:
You need a better quality video cable if you shove higher-frequency signals or have a long run. But Video signals are in the upper KiloHz (Thousands of cycles per second). Sub-woofer frequencies are below 120 hz (a big difference).
Because the subwoofer frequencies are much lower, nearly any good cable will work.
And because Video signals are so fast, it is necessary to use a 75 ohm cable to match the electronics.
But audio signals are much lower-frequency and it does not require a cable that matches the electronics. You can find audio cables made with 50/75/110/300 ohm coax and most of the time they work fine (assuming the L/R cables are both made with the same stuff )
Since CATV coax is cheap and plentiful, it works well when you need a 20 foot or longer cable.
But CATV coax is stiff and ugly so if your length is short enough, nearly any RCA style interconnect will do.
Does this help?

 

[Geoff I]

Thanks very much for the info, John and Bob.

 

[John Coleman]

Geoff,
It is my pleasure to help you out. Please let me know if you have any further questions.
Bob,
Thanks for the kind words. I chose to work in the audio/video industry because I have not only a passion for audio and video electronics, but I also have a passion for helping others maximize their entertainment experience.
Having said that, I appreciate the opportunity to share what I know about audio and video cables and connections. I believe in premium cables, but more importantly, I believe in helping others do what makes the most sense in their setup. Thanks