a/v cables for component video???

Discussion in 'Beginners, General Questions' started by Bob Kavanaugh, May 24, 2003.

  1. Bob Kavanaugh

    Bob Kavanaugh Second Unit

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    Alright, please help me to help out my friend.

    He has a Toshiba 34HF81 and a Toshiba progressive scan dvd player. The thing is, he has his component video hooked up with old monster a/v cables ( you know L audio R audio and composite video in one cord). Sure, it works, but I think it is tragic to hook up a 2500 dollar digital tv's video with some audio cables.

    Maybe I am crossing the line, by offering advice that is not asked for, and he tells me he is pleased with the video quality. I've offered to set up a double-blind test with my component cables, and he is not interested... yet. I think that if I come up with a good reason(s) for him to get real cables he'll do it.

    So... what would be the reason YOU would not use a/v cables for component video ,or would you, and I am the one who is wrong here?

    Thanks.
     
  2. MikeShea

    MikeShea Agent

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    If they're decent quality monster audio cables, they are probably fine. I've seen some relativly inexpensive Monster component cables for the $40 pricetag. You can always pay more but I doubt if you can ever justify the cost.
     
  3. Inspector Hammer!

    Inspector Hammer! Executive Producer

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    Bob,

    this "friend" is you isn't it? Come on, you can admit it. I'm kidding. [​IMG]

    To be quite honest Bob, I would NEVER use those types of cables for progressive scan or componant video and I would advise anyone who has progressive and componant video capability to go and pick up a set of real componant cables that are designed to carry that particular signal.

    Your friend may be getting signal degradation by using those types of cables for componant, in fact I can almost guarentee he is. If you were to test those cables using the resolution patteren on the AVIA calibration dvd, he's probably got video noise like mad with those cables, and that noise is present in his picture all the time. It's not hard to upgrade to the real cables and his picture quality would probably be better once or if he does so.

    But, RCA A/V cables used as componant cables, nope. You could always pick up a set for him and have him pay you back, just a friendly suggestion. [​IMG] Either way, try as hard as you can to steer him from the cables he's currently using.

    His equipment is only as good as the cables used to connect them, if he's got good equipment, he's shortchanging it's performance by skimping.

    Good luck. [​IMG]
     
  4. Allan Jayne

    Allan Jayne Cinematographer

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    If you pick up a set of audio cables regardless of price and use them for video, you will get a picture, but the quality is unpredictable. The longer the cable, the more likely you will see degradation.

    If you were lucky, the audio cable might actually be video grade, for example if during manufacture they made all three cables in the set from the same spool of wire for manufacturing simplicity.

    If your friend never complains about the picture, leave him alone. But if he ever tries calibrate or run a test pattern, let him know that all bets are off unless he upgrades the cables. Even what looks like misconvergence can be blamed on the cables as chroma delay and he could waste money on a service call there.

    Video hints:
    http://members.aol.com/ajaynejr/video.htm
     
  5. Bob McElfresh

    Bob McElfresh Producer

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    You could try telling him these facts:

    - Video cables should be made with 75 ohm coax.

    - Audio cables can be made with any of the popular impedences: 50, 75, 110, 300 ohms

    (Sometimes the L/R/Video bundles were all made with 75 ohm coax - this might be why your friend is getting away with it.)

    While you CAN use component cables for progressive/HD, the 3 video formats have different maximum frequency:

    Component Video: 4 Mhz
    Progressive Video: 13 Mhz
    1080 HD Video: 35 Mhz

    So for HD, you really want cables designed for HD, not just component.

    If you do get some different cables and try a comparison, DONT just fire up a DVD and look for differences. It's hard to notice/remember the fine details on moving pictures.

    Get a copy of Avia (the setup DVD) and pick some of the static, fine-focus or contrast test patterns. Do the A/B comparison with one of these patterns frozen on the screen.
     
  6. Bob Kavanaugh

    Bob Kavanaugh Second Unit

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    Thanks guys. No, this friend isn't me [​IMG] .

    We each have the Avia calibration disc, so i'll see if he's up to doing a heads up comparison. Sounds like that might work.

    Thanks!
     
  7. ChristW

    ChristW Agent

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    So how does this differ from using RG6 cable and attaching the correct connector to each end? I've read in numerous places that this works fine and am thinking about doing it in my theater (which just began construction this past weekend!)

    CW
     
  8. Bob McElfresh

    Bob McElfresh Producer

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  9. DaveWUSAF

    DaveWUSAF Auditioning

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    Cable TV frequencies go alot higher than just 1 Mhz. Ch 2 starts at about 54 Mhz and the upper channels on a small system are between 450 and 650 Mhz. RG-59 handles it fine on shorter runs but I agree that RG-6 would be the better choice for use in a home theater setting. I would imagine that you would loose less than 1/4 db from the lowest freqs to the highest (1 to 30 Mhz)in a pair under 6 ft long.
     

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