I shall diverge, but for the briefest of moments, from the more "traditional" warning methods to something slightly more...applicable.
I was having a discussion with a friend of mine over at
Ask the Motherboard (which is exactly what it sounds like: a sentient computer housed in a secret government facility that rather than take control of the entire US nuclear arsenal and bring about the fall of man like it was supposed to, started a blog. To avoid having to admit failure the designers locked it in a closet with an EZ Bake Oven and the complete DVD collection of She-Ra and resolved to bring about the fall of man themselves) about why you should never, ever, EVAR buy a digital media cable over $5. As the discussion progressed, aside from passing the Turing test, it was suggested that I write a guest post about the difference between analog and digital signal, and then how it applies to buying cables. At the risk of guesting a post that went over everyone's head, I resolved to write a slightly more techie post here and translate it for there. Also because I had no other ideas for what to write here.
I probably won't get super technical as I'm not an EE and don't want to do the research that would be required if I were to start digging into things like signal processing and Fourier transformations (which I hate!) so it might be a simple copy paste job. Or not. Let's find out:
The Knut once regaled The Pietras and I with a tale of how he was buying a thing. Momentarily sidetracked onto a different story (likely involving cats) we had several beers and returned once more to the topic of him buying this thing. At the store where these things were sold he got into a debate with the sales person on why he did not need to buy the $100 Monster HDMI cable. The Knut told the sales person that he did not need the $100 Monster HDMI cable as he had a cheap $5 one at home that would suffice. The sales person pointed out that the $100 Monster HDMI cable was the best that money could buy and would offer the clearest and bestest signal quality between the thing he was purchasing and the thing he was connecting it to. The Knut pointed out that that was the most bat-shit insane thing he had ever heard as HDMI is a digital standard, that quality and clarity don't mean jack because it's comprised entirely of 1s and 0s and that as long as the cable is rated HDMI it meets the minimum requirements for transferring the 1s and 0s from thing 1 to thing 2. At this point, The Knut stopped channeling Theodor Geisel and told the sales person that he was, in fact, an EE. The sales person then sheepishly walked away and The Knut purchased his blu-ray player, went home and connected it to his TV using a cheap HDMI cable and proceeded to watch The Brady Bunch. The sound of a tiny bell ringing indicated that the cat had killed yet another rabbit.
I'm going to pause here and state several assumptions that I am making in posting this post: Assumption 1) You are not future proofing your setup. In other words you have a setup which you can easily access and change cables if necessary and not running them through walls. Assumption 2) You are not using cables over 2 meters. Assumption 3) You have things that you want to connect to each other at minimal cost.
First off, let's briefly, discuss the difference between analog and digital signals.
Analog technology uses the whole waveform. Each part of the wave is retained in it's original form. A vinyl record is a very good example of analog technology. In the case of vinyl, the waveform is actually imprinted into the record. This is why if you hold your ear right up to the needle you can hear the sound. As the needle bounces over the peaks and valleys it transmits electrical pulses in varying intensities to the speakers which make sound. In the case of analog, the amplitude (height/depth of the peaks and valleys) and the frequency (distance between them) are all variable. Theoretically an analog signal has infinite resolution, though in practice it is much more susceptible to noise.
Digital technology, on the other hand, uses a discrete waveform to transmit information. Essentially a 1 or a 0, on or off. While still susceptible to noise, the impact is far less than that of analog technology allowing for enhanced error correction, better compression and a host of other digital only features.
As an example: let's imagine an old school TV with old school bunny ears. You adjust the bunny ears to make the picture clearer or nosier. What you're doing is adjusting the equipment to receive a specific frequency. The change in amplitude is what makes the picture and sound. Notice though, that it doesn't have to be super clear. You can adjust it so that you can still see bits of the TV show, but there's a whole lot of noise.
By contrast, imagine one of them fancy new fangled High Definition HDTV Television screens with the digital cable/dish/UVerse/FIOS/etc and the fancy DVR recorder (redundant statement is redundant). I'm sure you all have seen the occasional block or weird looking bit of picture using one of these setups, or when the picture suddenly looks like a Picasso. In analog the old TV can still pick up some of the original picture because even though the signal is distorted it is still receiving bits of the original signal. But with a digital signal, when you see your setup go crazy it's because it's not actually getting any information. Because a digital signal is either on, or off, if the TV can't tell which it is because of a low signal quality, or if the error correction function fails to properly functionally correct for error, it does the best it can. Which is to just put that garbled mess up on the screen, or if it's really bad, nothing at all.
So this brings us to The Knut's argument with the sales person about the HDMI cables and also why you should never buy expensive ones. HDMI is digital. This means that the information is either going to get there, or it's not. If it gets there your picture will be perfect. If it doesn't you will not have a picture. A cable can only be rated HDMI if it meets the minimum requirements for transmitting the 1s and 0s. As such, even though they're cheap, because the cheap cables are rated HDMI, they are able to transmit 1s and 0s. The quality of the signal doesn't matter.
To be clear I am primarily talking about HDMI cables as they are the most common source of rip off in the cable market. But the same can apply to other cables, such as USB, Ethernet, coax, and even speaker cables. Unless you're transmitting over a long distance (which my previous assumptions assume that you are not) where shielding and noise are going to have a measurable impact on your signal, you can get by just fine with the cheaper cables/wires. I did buy a 7.5 meter HDMI cable once to hook my computer up to the TV on the other side of the room. I bought the cheapest one I could find, $25. Not a single problem.
I'd recommend checking out
Newegg for anything and everything tech related that you need.
Amazon can be a good source two, especially if you're a prime subscriber, though I find the comments from Newegg to be infinitely more helpful. Find the type of cable you want at the length you want and then find the cheapest one. I will concede that on occasion I've come across a cheap ($1-3) HDMI or USB cable that doesn't fit well, but reading a few of the comments should indicate whether or not this is an issue. And even the loose fitting ones that I have work just fine, because in the case of HDMI cables, your'e not messing around with them once they're in.
Now you should be well informed as to why you should never buy an expensive cable. However, if you absolutely, positively, unquestionably have to have it that exact moment (i.e. you're hosting a double feature of "The Room" and "Birdemic: Shock and Terror" in 15 minutes and for some reason you're only just now putting your setup together) then my suggestion is to go find the cheapest one you can at the store, order the even cheaper one, and return it when the even cheaper one comes in (unless you're one of the lucky folks who lives near a store that sells cheap cables in which case just buy the cheap one in the store).
In fact, as a general rule: never buy accessories (game controllers, cables, remotes, etc) in a brick and mortar and glass and iron and carpet and drywall and wood and tile store. They are almost always cheaper online.
In fact as a generaler rule: price compare. Everything. It's not that hard, especially if you have a smartphone. Even if you don't. Sometimes it is actually cheaper in the store (if it's a $5 part why are you going to pay $5 in shipping as well?). Sometimes the item in the store is $127.45 and online it's $124.21. If you care that much about $3.24 then...I'm sorry.
I would go on about buying $200 surge protectors...but I'll leave that for another day.
The interesting thing about The Knut is that if you interrupt his story, no matter how long the interruption, no matter if the group then disperses, he will pick up right were he left off the next time you see him. That is, if he hasn't hunted you down first to finish.
