Analog vs. Digital: Don't be fooled

[Robert Maxwell]

Back when all audio and video were analog in nature, it very much did matter what cables and wires you used. Some were better at thwarting interference. Some carried the signal farther with less degradation. That doesn't mean those $50 gold-plated Monster cables actually improved quality by a tremendous amount, but the composition and manufacturing quality of analog cables does have an effect on the final output. This has led to all sorts of snake-oil salesmanship in the home theater/audio space, such as the aforementioned (and perennial whipping boy) Monster.

But now we've gone (or are at least going) digital. The key difference in digital is that the nature of the cable carrying the data does not matter. Either the signal gets to the end in one piece, or it gets corrupted along the way--meaning you either get no output at all, or unintelligible garbage. But slight, almost-imperceptible quality variations depending on the cable's manufacture? Nah, doesn't really happen with digital.

Even so, you still have instances like this: Link

“My only guess is that the Super SATAs reject interference significantly better than the standard cables and in so doing lower the noise floor revealing greater low-level musical detail and presentational improvements in the soundstage and the ‘air’ around instruments.”

The above, as the linked article explains, is pure nonsense.

I imagine most of the regulars in SciTech are already aware that digital signals don't work anything like analog ones, but I wanted to post this in the hopes of educating people who may not have known. Don't be conned into buying expensive digital cables. There's really no benefit. Either the cable works or it doesn't. Odds are, that cheapo $5 cable you bought from Cables Unlimited will work just as well as the $150 one the Best Buy sales rep tried to push on you.

Be smart: don't let the digital snake-oil salesmen fool you.

 

[Amaris]

Back when all audio and video were analog in nature, it very much did matter what cables and wires you used. Some were better at thwarting interference. Some carried the signal farther with less degradation. That doesn't mean those $50 gold-plated Monster cables actually improved quality by a tremendous amount, but the composition and manufacturing quality of analog cables does have an effect on the final output. This has led to all sorts of snake-oil salesmanship in the home theater/audio space, such as the aforementioned (and perennial whipping boy) Monster.

But now we've gone (or are at least going) digital. The key difference in digital is that the nature of the cable carrying the data does not matter. Either the signal gets to the end in one piece, or it gets corrupted along the way--meaning you either get no output at all, or unintelligible garbage. But slight, almost-imperceptible quality variations depending on the cable's manufacture? Nah, doesn't really happen with digital.

Even so, you still have instances like this: Link

“My only guess is that the Super SATAs reject interference significantly better than the standard cables and in so doing lower the noise floor revealing greater low-level musical detail and presentational improvements in the soundstage and the ‘air’ around instruments.”

The above, as the linked article explains, is pure nonsense.

I imagine most of the regulars in SciTech are already aware that digital signals don't work anything like analog ones, but I wanted to post this in the hopes of educating people who may not have known. Don't be conned into buying expensive digital cables. There's really no benefit. Either the cable works or it doesn't. Odds are, that cheapo $5 cable you bought from Cables Unlimited will work just as well as the $150 one the Best Buy sales rep tried to push on you.

Be smart: don't let the digital snake-oil salesmen fool you.

Did that for a guy at Walmart the other day. He was looking at the HDMI cables after buying an HDTV, and after a minute of looking, was starting to pick up a 6' HDMI cable for $32. I (politely) broke the ice by asking what kind of TV he bought. After he told me, I said to him, "You don't have to pay $32 for an HDMI cable. Amazon sells them for $1, and they're just as good. In fact, I own 4 HDMI cables and paid about 83 cents a piece for them, and one of them is a 10' cable. The picture quality is superb, and I paid a grand total of $10 for all four. You can get that 6' HDMI cable for about $4 at Amazon." He was surprised, but I swore by it, so he called his friend and told him to go to Amazon.com. A minute later he closes the phone and thanks me for saving him a bunch of money.

I just have this thing about people being ripped off like that.

 

[Robert Maxwell]

Good story!

I would point out that this holds true for basically all computer cables, too. A USB cable is a USB cable. A CAT5 Ethernet cable is a CAT5 Ethernet cable. Those expensive cables are just how stores rip off people who don't know any better.

 

[ITL]

Good story!

I would point out that this holds true for basically all computer cables, too. A USB cable is a USB cable. A CAT5 Ethernet cable is a CAT5 Ethernet cable. Those expensive cables are just how stores rip off people who don't know any better.

A while back I needed a USB extension cable. My local shop only stocked expensive ones - I could have got a cheap one for a fraction of the price from a pound shop in the next town. But paying more than the cable was worth in bus fares to get to there was pointless. So I had to get the expensive one. Rip off swine!

 

[Marc]

Good story!

I would point out that this holds true for basically all computer cables, too. A USB cable is a USB cable. A CAT5 Ethernet cable is a CAT5 Ethernet cable. Those expensive cables are just how stores rip off people who don't know any better.

Well the cable might be CAT5 but there still can be some difference and then there's the construction.

But that doesn't excuse the prices stores charge for ethernet cables. Haven't looked here but back home I could by cables from a whole sale for a just over a buck a piece including tax.

Go into a retail store and the same length cable is selling for $20+.

 

[clint g]

Good story!

I would point out that this holds true for basically all computer cables, too. A USB cable is a USB cable. A CAT5 Ethernet cable is a CAT5 Ethernet cable. Those expensive cables are just how stores rip off people who don't know any better.

A while back I needed a USB extension cable. My local shop only stocked expensive ones - I could have got a cheap one for a fraction of the price from a pound shop in the next town. But paying more than the cable was worth in bus fares to get to there was pointless. So I had to get the expensive one. Rip off swine!

Yeah, this happened to me recently as well. I was in a bind, needed to print something, and couldn't find the damn cable. 26 bucks later I had a new USB cable

 

[JarodRussell]

Though with bad cables you get a lot of noise and dampening and then you'll get bit errors.

 

[TheBrew]

Though with bad cables you get a lot of noise and dampening and then you'll get bit errors.

There is no "noise" with digital signals. Either you get the data or you don't.

 

[Lindley]

Though with bad cables you get a lot of noise and dampening and then you'll get bit errors.

There is no "noise" with digital signals. Either you get the data or you don't.

I think what is meant is that if your cables are really bad, then you're more likely to not get the signal now and then.

 

[Rii]

Though with bad cables you get a lot of noise and dampening and then you'll get bit errors.

There is no "noise" with digital signals. Either you get the data or you don't.

He's referring to EMI and impedance mismatching generating bit errors. Maybe the hardware at the other end catches it and re-requests the data, in which case it 'only' costs you performance, and maybe it doesn't*, in which case you can wind up with corrupt files or even a system crash. This is why interfaces like PATA have cable specifications in the first place. And if you're going outside those specifications, by, say, using a 1m PATA cable, then you'll probably want to be doing something to mitigate the issues that led to those specifications in the first place, i.e. shielding the cable and not using it to connect hardware created in the early years of the interface.

* CRC - which is about the fastest and most widely used error-detection method - will not reliably catch multiple errors in a given block of data.

 

[Pingfah]

I used to work at a newspaper and someone once asked me if a digital photo could fade if you used it enough times. No shit.

I'm not sure what he thought he meant by "used" even. Opened? Printed?

 

[JarodRussell]

I used to work at a newspaper and someone once asked me if a digital photo could fade if you used it enough times. No shit.

I'm not sure what he thought he meant by "used" even. Opened? Printed?

Well, hey, in a way, it even does. Save a jpeg at medium quality multiple times, and you'll see what I mean (and I've seen people who do that. Instead of copying the files, they open them and save them to the new location). Compression can be the digital equivalent to analog noise.

 

[Meredith]

There are 10 types of people who think they understand digital, those who do and those who don't.


I laugh at the fools who pay 100 dollars for a HDMI monster cable. Unless you are running more than 9ft of the stuff even a mediocre cable will work just fine as long as it doesn't come out of the box with a glaring defect.

 

[Meredith]

I used to work at a newspaper and someone once asked me if a digital photo could fade if you used it enough times. No shit.

I'm not sure what he thought he meant by "used" even. Opened? Printed?

Well, hey, in a way, it even does. Save a jpeg at medium quality multiple times, and you'll see what I mean (and I've seen people who do that. Instead of copying the files, they open them and save them to the new location). Compression can be the digital equivalent to analog noise.

Yeah, for instance if you compress an MP3 over and over and over again, you will start hearing compression artifacts until they overtake the file and it sounds like screechy dirt, but if you use something like FLAC or some other loss less compression you will have no issues.

 

[Pingfah]

I used to work at a newspaper and someone once asked me if a digital photo could fade if you used it enough times. No shit.

I'm not sure what he thought he meant by "used" even. Opened? Printed?

Well, hey, in a way, it even does. Save a jpeg at medium quality multiple times, and you'll see what I mean (and I've seen people who do that. Instead of copying the files, they open them and save them to the new location). Compression can be the digital equivalent to analog noise.

Ah yes, quite true, but we don't use lossy compression to store pictures, he was asking about the banner we use daily. Obviously we wouldn't be opening and resaving in a lossy format it every day, that would be ridiculous. He meant fade, in the same way that a photo would fade if you left it out in the sun.

 

[Amaris]

I used to work at a newspaper and someone once asked me if a digital photo could fade if you used it enough times. No shit.

I'm not sure what he thought he meant by "used" even. Opened? Printed?

Well, hey, in a way, it even does. Save a jpeg at medium quality multiple times, and you'll see what I mean (and I've seen people who do that. Instead of copying the files, they open them and save them to the new location). Compression can be the digital equivalent to analog noise.

Ah yes, quite true, but we don't use lossy compression to store pictures, he was asking about the banner we use daily. Obviously we wouldn't be opening and resaving in a lossy format it every day, that would be ridiculous. He meant fade, in the same way that a photo would fade if you left it out in the sun.

Did you tell him yes? Tell me you told him yes.

 

[Robert Maxwell]

Well, hey, in a way, it even does. Save a jpeg at medium quality multiple times, and you'll see what I mean (and I've seen people who do that. Instead of copying the files, they open them and save them to the new location). Compression can be the digital equivalent to analog noise.

Ah yes, quite true, but we don't use lossy compression to store pictures, he was asking about the banner we use daily. Obviously we wouldn't be opening and resaving in a lossy format it every day, that would be ridiculous. He meant fade, in the same way that a photo would fade if you left it out in the sun.

Did you tell him yes? Tell me you told him yes.

If I'm ever called upon to teach someone how to copy files, I'll only teach them the "Cut / Paste" method, so it will work just like in Star Trek--you get one copy, ONE COPY, and if you screw up, it's gone. Backups are for the weak!

 

[Amaris]

Ah yes, quite true, but we don't use lossy compression to store pictures, he was asking about the banner we use daily. Obviously we wouldn't be opening and resaving in a lossy format it every day, that would be ridiculous. He meant fade, in the same way that a photo would fade if you left it out in the sun.

Did you tell him yes? Tell me you told him yes.

If I'm ever called upon to teach someone how to copy files, I'll only teach them the "Cut / Paste" method, so it will work just like in Star Trek--you get one copy, ONE COPY, and if you screw up, it's gone. Backups are for the weak!

"It's gone."
"How'd that happen?"
"You messed up."
"Can I get it back?"
"No."
"Why not?"
"Because you failed."

That's a harsh lesson.

 

[Robert Maxwell]

Did you tell him yes? Tell me you told him yes.

If I'm ever called upon to teach someone how to copy files, I'll only teach them the "Cut / Paste" method, so it will work just like in Star Trek--you get one copy, ONE COPY, and if you screw up, it's gone. Backups are for the weak!

"It's gone."
"How'd that happen?"
"You messed up."
"Can I get it back?"
"No."
"Why not?"
"Because you failed."

That's a harsh lesson.

Some people really do think that's how computer files work. The very notion of backups is not something they can comprehend.

 

[Nomad V]

This may beside the point, but why do HDMI cables cost so much? Compared to Coax HDMI seems insanely expensive.