Cheap Cables? Well Mostly

This post advocates always buying the cheap home theater cables.  I agree up to a point.  I have never been able to hear the difference in really, really expensive cables, say for 3 foot interconnects.

But there is an exception to this, and it is interesting the author Glen is quoting actually uses this example -- long runs of video cable, particularly HDMI.  If your TV sits on top of your video source, and the video run is 6 feet or less, then the average person with the average equipment will not notice the difference in video cables.  But should your cable run extend to, say, 25 feet or more, then you are going to have problems.  Video is both very high bandwidth and very susceptible to noise.  HDMI and other digital cables are no exception  -- the only thing that changes are the symptoms. 

In an analog cable, you will start getting a lot of video noise with longer cable runs.  Computer VGA cables were notorious for this -- if you went more than 6 feet, your picture could be a real mess.  SVGA S-video also had such problems.  Now, with digital cable, the picture does not gain noise but at some point the signal is lost altogether and the picture drops out completely -- think of a youtube video streaming over a bad wireless connection.   I will about gaurantee this will happen with 25 feet of JC Penny HDMI cable.

  • Tim

    I have a 30 ft run to make for my new 58 inch plasma. I am remote locating the box and running the cable throught the ceiling. I plan to buy a cheap cable, see how it works and return it if it doesn't. I will let you know how it goes.

  • markm

    Tim: whether that's a smart move or not depends on how you value your time to run that cable - maybe twice. If you're paying someone else $50/hour to run cable, it nearly always pays off to start with good enough parts that it will work first time.

  • JohnF

    The thing is that all HDMI cable is transmitting, I think, is digital info--zeros and ones. Even if there is a lot of noise in the line, the receiving equipment can pretty easily tell whether its getting a zero or a one. I don't think it's a bandwidth issue at all.

    Analog signals are another matter, as you observe.

  • Rob

    The word you are hunting for is attenuation. Translation, signal loss.

    This not the only problem, but it is the biggest one.

    Analog degrades gracefully. It becomes less and less viewable as the signal is attenuated, but the analog circuits will continue to attempt to present something, until almost the bitter end. The viewer will generally give up long before the electronics do.

    Digital is all about ones and zeros. Don't buy the hype that a one is a one and a zero is a zero. They may be on paper, but in an electronic circuit, they are represented by high and low voltage levels (perhaps low and no voltage levels). When the signal becomes attenuated it becomes very difficult for the receiving end to determine if that was a one or a zero that just arrived.

    Add to this poor termination (often not a cable problem, but the electronics make assumptions about the performance of the cable of the incoming signal quality) and the resulting signal reflections (which would display as ghosting in analog) and digital is actually quite fragile.

    When it works, it works really well. My recording studio is digital. I worked in analog and while it had its allure, I'll take digital thank you.

    All this to say that yes, even in digital, wires matter. Fatter is generally better, but watch out for crummy wire that is fatter as a selling point. You want low capacitance, low loss wire regardless of what it is called or who made it.

    For short runs it is almost a who cares deal. At more than 4 feet pay some attention. At more than ten feet pay a lot of attention. At greater than twenty feet consider paying a professional. At greater than thirty feet, consider prayer. Okay, perhaps over the top, but the further you go the tougher it gets.

    As to bandwidth, that is shorthand for low capacitance. The lower the capacitance, the higher the bandwidth. And, BTW: If you want good sharp transitions from zeros to ones and ones to zeros, you want high bandwidth, because the rise time is very fast and it is this rise time that becomes a problem. Think of rise time as acceleration from 0 to 60 (zero to one). Your digital "car" will need good brakes too (one back to zero). Poor bandwidth is the rough equivalent of wet pavement.

  • Bob Smith

    Check out this article:

    What's the Matter with HDMI?
    http://www.audioholics.com/education/cables/whats-the-matter-with-hdmi

  • Anon

    Don't buy the hype that a one is a one and a zero is a zero. They may be on paper, but in an electronic circuit, they are represented by high and low voltage levels

    In other words, all cables are analog. There is no such thing as a digital cable.

  • HTRN

    Keep in mind, most really expensive cables are expensive because they can get away with it because of clever marketing, not because of actual manufacturing costs.(cough, Monstercable, cough).

    If you want good cables, that aren't priced like designer handbags, check Monoprice and Blue Jeans cable. Both have high quality products, without the boutique prices of some of the other brands.

  • Erik The Red

    Obligatory link: Best commentary on Monster Cable ever:

    http://www.somethingawful.com/d/news/monster-monsters.php

  • Erik The Red

    And the guys at Penny Arcade parody the Evil Monster:

    http://www.penny-arcade.com/comic/2002/11/25 (warning - their site is slow right now).

    Now go back and read the Something Awful link above that you probably skipped because you didn't want to read something from a domain like somethingawful.com. You don't want to miss quotes like this:

    Of course these wires cost nearly as much as the DVD player itself, even more if you include the Monster-brand power filtration adapting converter unit which instantly converts your cash into lines of high grade Columbian cocaine for the company's CEO.

    and this:

    Now I'm all for ridiculous lawsuits and people trying to sue window manufacturers for failing to plaster their products with a few hundred stickers labeled "DO NOT TRY TO CHEW OR MAKE LOVE TO THE GLASS," because that kind of shit makes me laugh until I stop. But everything about Monster's company and their pro-alienation business plan seems just mind-bogglingly outrageous.

    I'll stop badgering you now.

  • Mesa Econoguy

    Regardless of how shielded your cable is, the longer the cable, the greater the interference (any cable with current running acts as an antenna) and potential noise.

    Noise gates, digital or analog, only filter out so much, so get ready to shell out a buncha money if you live on top of a hill with a microwave tower.

    Monstercable does actually work, in certain configurations.

    In the end, your sound output is only as good as your 1) amplifier, and 2) speakers. The purest reproduction would be with a D/A converter at the speaker.

  • bob r

    "Computer VGA cables were notorious for this -- if you went more than 6 feet, your picture could be a real mess."

    Check out these:
    http://myhometheater.homestead.com/vgacable.html
    http://www.avsforum.com/avs-vb/showthread.php?s=&threadid=23850&highlight=cat5

    They are getting good results up to 50 feet using shielded CAT5 Ethernet cable for video.

  • http://www.ictradingonline.com Martina

    What a embllishing this cheap cables is very stagger.