Here's a common scenario: you just picked up some new electronic gizmo off the shelf at your favorite local electronics retail outlet, and you've got a sales guy "helping" you. He proceeds to tell you that if don't get this magical $80 cable, your purchase is going to look or sound no better than that $20 piece of garbage sitting a few feet down the shelf that looks like it'd fall apart if you breathed on it. Is he telling the truth, or is it a farcical sales pitch?
In the A/V cable world, there seems to be no end to cable selections. Take speaker cable, for example. You could get your average 14AWG speaker wire for around $0.50/ft, or you could splurge a bit and get AudioQuest's speaker cable for $9400 for 3 feet. Somewhere in between lies a plethora of cable options, not to mention all of the marketing telling you how each manufacturer's cable is better than the "leading competitor". How are you able to tell what you actually need and what's just a waste of money? As one of my engineering profs liked to say, "V=IR. You've got all the components, just bang it out!"
Let me explain. Any audio or video signal is really just an electrical signal. Electrical signals really don't like resistance. If you have too much resistance, your signal isn't going to get to the destination like it was intended. Look back at that equation: V=IR, where V is voltage, I is current, and R is resistance. If you make R large while V stays constant, I has to decrease (no, that's not a grammatical mistake, I'm talking about current, not me, you nimwit). You might ask something like, "What causes this resistance, and how do I get rid of it?" Thanks for asking, I was about to answer that! About all you have to do is make sure you have the right wire size for the right job. The larger the wire, the less resistance. If you pick too small a wire for the current you're throwing through the wire and the length of your run, you'll get too much resistance. If you're talking about speaker wires, your lows won't hit as hard and your highs will sound a little muddled.
Speaker wires are an easy one because the signal being sent to the speaker is a higher voltage than most other A/V signals. Another problem with cables is their ability to pick up RF (radio frequency) noise. This may be a feature depending on the cable's intended use (say, a radio antenna). All cables essentially are an antenna, and this RF noise induces a small voltage and current in a wire. The longer the cable, the more RF noise it will pick up. In pretty much all scenarios (save for that antenna), this is a bad thing. Since an audio amplifier is putting out a signal with a higher voltage compared to a CD player, the speaker signal is less affected by that small induced voltage than the CD player signal. The RF noise on the CD player signal is a larger percentage of the actual signal's strength. While this is a problem with professional installations where cables are commonly run 100' or more, you most likely won't run in to this if you're setting up your own home theater or sound system. Cables usually have some sort of built in shielding from this RF noise, and this is good enough for short runs.
I would like to caveat myself here, though. Under some certain circumstances, you can really shoot yourself in the foot. That circumstance looks something like this. Or if you create a huge magnetic field by wrapping a power cable up in a loop and running a signal cable through it. That would do it too.
Aside from those instances, you won't notice much of a difference. Suffice it to say that if you got a range of decent quality cables together and had a critical listening session with an unbiased audiophile (one not biased by paychecks from supporting companies or by the IJustBoughtThisMillionDollarCableSoItMustSoundBetter syndrome), there would be no audible difference. Sure, there might be a lab test measurable difference, but can any human actually hear that difference? The answer is usually no. I have actually heard of tests done with a metal clothes hanger pitted against high-dollar audiophile speaker cable (think of that $80 cable the sales guy told you that you just have to buy). Yep, no difference. It's all about resistance, and if you have picked a large enough wire for the distance you're going, you won't hear any improvement (unless you have that aforementioned syndrome).
It gets even better when you talk about digital signals. Think of digital TV over-the-air broadcasts. You either get a signal or you don't. There aren't any in betweens like analog TV, where you could get a perfect picture, complete static, or anything between the two. Digital signals are either there or they aren't. Sure there can be a DC offset voltage induced or some RF noise, but because of digital circuitry, most of that disappears when it gets interpreted by the receiving device. This is one of the main reasons why digital signal transmission works much better in non-ideal circumstances compared to analog transmission. If you're dealing with analog video cabling, the picture will depend upon the length of the cable. If you have two video displays hooked up with analog video cables, one cable being 3' long and the other being 50' long, the same image will look different because of the signal loss caused by the longer cable (longer cable equals higher resistance). If you had the same two computers hooked up with DVI (digital) cables, run the same distances as before, you wouldn't notice a picture difference.
Here is also an example of my point before about resistance. Some of you nerds out there (FOSO!!!) will have already thought something along the lines of, "Hey wait a minute, you can only run DVI 15 feet!" That is true, but some manufacturers have found ways to make the cable such that you can run longer than that 15' limitation. The secret there lies with...can you guess? Larger gauge wire! These cables are easily twice as thick as the DVI cable that came with your monitor. If you start pushing the limits of a digital video signal, you will start to see "green sparklies" right before you lose signal. These sparklies (yes, that's a technical term) are really just artifacts of data not being there when the receiving device expects it to be there.
So what does this all boil down to? Parts Express and Monoprice. Don't spend lots of money on cables and don't run audio or video cables right next to (or through loops of) power cords.
Further reading if you made it this far and are looking for some more punishment.
In the A/V cable world, there seems to be no end to cable selections. Take speaker cable, for example. You could get your average 14AWG speaker wire for around $0.50/ft, or you could splurge a bit and get AudioQuest's speaker cable for $9400 for 3 feet. Somewhere in between lies a plethora of cable options, not to mention all of the marketing telling you how each manufacturer's cable is better than the "leading competitor". How are you able to tell what you actually need and what's just a waste of money? As one of my engineering profs liked to say, "V=IR. You've got all the components, just bang it out!"
Let me explain. Any audio or video signal is really just an electrical signal. Electrical signals really don't like resistance. If you have too much resistance, your signal isn't going to get to the destination like it was intended. Look back at that equation: V=IR, where V is voltage, I is current, and R is resistance. If you make R large while V stays constant, I has to decrease (no, that's not a grammatical mistake, I'm talking about current, not me, you nimwit). You might ask something like, "What causes this resistance, and how do I get rid of it?" Thanks for asking, I was about to answer that! About all you have to do is make sure you have the right wire size for the right job. The larger the wire, the less resistance. If you pick too small a wire for the current you're throwing through the wire and the length of your run, you'll get too much resistance. If you're talking about speaker wires, your lows won't hit as hard and your highs will sound a little muddled.
Speaker wires are an easy one because the signal being sent to the speaker is a higher voltage than most other A/V signals. Another problem with cables is their ability to pick up RF (radio frequency) noise. This may be a feature depending on the cable's intended use (say, a radio antenna). All cables essentially are an antenna, and this RF noise induces a small voltage and current in a wire. The longer the cable, the more RF noise it will pick up. In pretty much all scenarios (save for that antenna), this is a bad thing. Since an audio amplifier is putting out a signal with a higher voltage compared to a CD player, the speaker signal is less affected by that small induced voltage than the CD player signal. The RF noise on the CD player signal is a larger percentage of the actual signal's strength. While this is a problem with professional installations where cables are commonly run 100' or more, you most likely won't run in to this if you're setting up your own home theater or sound system. Cables usually have some sort of built in shielding from this RF noise, and this is good enough for short runs.
I would like to caveat myself here, though. Under some certain circumstances, you can really shoot yourself in the foot. That circumstance looks something like this. Or if you create a huge magnetic field by wrapping a power cable up in a loop and running a signal cable through it. That would do it too.
Aside from those instances, you won't notice much of a difference. Suffice it to say that if you got a range of decent quality cables together and had a critical listening session with an unbiased audiophile (one not biased by paychecks from supporting companies or by the IJustBoughtThisMillionDollarCableSoItMustSoundBetter syndrome), there would be no audible difference. Sure, there might be a lab test measurable difference, but can any human actually hear that difference? The answer is usually no. I have actually heard of tests done with a metal clothes hanger pitted against high-dollar audiophile speaker cable (think of that $80 cable the sales guy told you that you just have to buy). Yep, no difference. It's all about resistance, and if you have picked a large enough wire for the distance you're going, you won't hear any improvement (unless you have that aforementioned syndrome).
It gets even better when you talk about digital signals. Think of digital TV over-the-air broadcasts. You either get a signal or you don't. There aren't any in betweens like analog TV, where you could get a perfect picture, complete static, or anything between the two. Digital signals are either there or they aren't. Sure there can be a DC offset voltage induced or some RF noise, but because of digital circuitry, most of that disappears when it gets interpreted by the receiving device. This is one of the main reasons why digital signal transmission works much better in non-ideal circumstances compared to analog transmission. If you're dealing with analog video cabling, the picture will depend upon the length of the cable. If you have two video displays hooked up with analog video cables, one cable being 3' long and the other being 50' long, the same image will look different because of the signal loss caused by the longer cable (longer cable equals higher resistance). If you had the same two computers hooked up with DVI (digital) cables, run the same distances as before, you wouldn't notice a picture difference.
Here is also an example of my point before about resistance. Some of you nerds out there (FOSO!!!) will have already thought something along the lines of, "Hey wait a minute, you can only run DVI 15 feet!" That is true, but some manufacturers have found ways to make the cable such that you can run longer than that 15' limitation. The secret there lies with...can you guess? Larger gauge wire! These cables are easily twice as thick as the DVI cable that came with your monitor. If you start pushing the limits of a digital video signal, you will start to see "green sparklies" right before you lose signal. These sparklies (yes, that's a technical term) are really just artifacts of data not being there when the receiving device expects it to be there.
So what does this all boil down to? Parts Express and Monoprice. Don't spend lots of money on cables and don't run audio or video cables right next to (or through loops of) power cords.
Further reading if you made it this far and are looking for some more punishment.
