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View Full Version : Is "Digital Technology" Really Better?



Rogue
9/3/2007, 08:05 AM
Or is someone just making an assload of money from it?

My old analog cell phone worked great, almost everywhere. When there was a low signal, it worked fine. Digital cell phone...not so much. It's either all there or not at all. And out here in the country where I live that is teh succ.

Digital cable teevee? Good when it works which is most of the time. When it doesn't it is "tiling" or freezing or completely gorked-out.

I'd trade 5 of these digital signal cell phones for 1 old analog one.

What's the deal with digital being marketed as superior when, in some ways, it is anything but?





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LilSooner
9/3/2007, 08:19 AM
I miss my old nokia 6120 that thing was indistructable!

85Sooner
9/3/2007, 08:27 AM
NO. its cheaper and more portable thats it

Frozen Sooner
9/3/2007, 11:29 AM
Uses less bandwidth, too.

But ask any audiophile whether they'd have a top-of-the-line digital amp or a MacIntosh analog amp.

crawfish
9/3/2007, 11:40 AM
Digital is a lossless technology - meaning, it doesn't lose any of its quality as it moves down the pipe. The same can't be said for analog. It also provides the capability to have a single pipeline for all kinds of data (the internet). I already get my cable TV/phone/internet through the same fiberoptic wire to my house.

sooneron
9/3/2007, 12:19 PM
Uses less bandwidth, too.

But ask any audiophile whether they'd have a top-of-the-line digital amp or a MacIntosh analog amp.
True Dat!

Frozen Sooner
9/3/2007, 02:04 PM
Digital is a lossless technology - meaning, it doesn't lose any of its quality as it moves down the pipe. The same can't be said for analog. It also provides the capability to have a single pipeline for all kinds of data (the internet). I already get my cable TV/phone/internet through the same fiberoptic wire to my house.

Are you sure that mobile phone transmission is lossless? I mean, if you say so, but it sure sounds lossy to me.

Vaevictis
9/3/2007, 02:08 PM
Are you sure that mobile phone transmission is lossless? I mean, if you say so, but it sure sounds lossy to me.

I believe the transmission itself is lossless.

The same cannot be said for the sampling. (... and strictly speaking, there's no such thing as lossless digital sampling.)

(and when I'm referring to "lossless" here, I'm talking about audio losses, not packet losses... wireless is a very error prone medium when it comes to pushing the raw data, and since the audio is encapsulated in the packets...)

Frozen Sooner
9/3/2007, 02:14 PM
Isn't DSD lossless sampling? I don't know why I think that, but it's stuck in my head for some reason.

Vaevictis
9/3/2007, 02:21 PM
It's impossible to do a lossless digital sample of an analog signal for two reasons:

1. Quantization noise. Basically, when you take a digital sample, you sample every X time period, and you record some single value that represents the signal over that time period -- this can be an instantaneous value at X time, an average over the time, whatever. But you're still losing information because the signal may not have taken that value over the whole time period.
2. Aliasing. To get a truly lossless signal, you'd have to have an infinitely fast sampler... at best, you can "safely" sample a bandwidth 1/2 of the speed of your sampler. You either need a bandpass filter of 1/2f on the front end, or you risk "folding" frequencies outside of your band back into your band. (ie, without the filter, if you were to sample at 44KHz, a signal at 23KHz would get "folded" back to 21KHz, and you would not be able to distinguish which part of the power at 21KHz is really 21KHz and which part is 23KHz.)

EDIT: Now that said, it may be possible to do good enough sampling that a human ear can't tell the difference...

Frozen Sooner
9/3/2007, 02:29 PM
Yeah, you're right. Logically the words "lossless" and "sampling" can't co-exist.

And DSD isn't lossless. I was mistaken. In fact, for some frequecies, it's not even as good as PCM.

Thanks for the erudition.

Vaevictis
9/3/2007, 02:32 PM
Well, technically, you can do a lossless sampling of a digital signal if you are sampling fast enough that you catch every single value as it comes down the pipe.

The problem with an analog signal is that because it's continuous, you can't possibly do discrete sampling fast enough to catch every single value.

Frozen Sooner
9/3/2007, 02:35 PM
Damn it, stop making me look stupid! :mad: ;)

If I'm talking about sampling, then I'm generally (99%) of the time talking about recreating an analog audio signal, so yeah. Of course, if what you have to begin with is a digital bitstream, of course you can up your sample rate to recreate it because you're only dealing with discrete values.

Vaevictis
9/3/2007, 02:41 PM
Heh, sorry. :)

I had a prof (Dr. Havlicek) who beat this into me a couple of semesters ago, so... :)

(Let's just say, you don't look nearly as stupid as I did... ;) )

slickdawg
9/3/2007, 02:45 PM
Digital, without exception.

TV: Less bandwidth, better picture.

Cell Phones: YOU CAN HEAR CONVERSATIONS WITH A SCANNER ON ANALOG, you can't on digital. Digital provides a better signal and no static.

Vaevictis
9/3/2007, 02:47 PM
And as far as whether or not digital technology is really better...

The answer is: It depends on how you define "better." Digital gets smaller faster, and has a nice price curve. If you don't mind carrying around a brick phone and paying more, analog might be a little bit better.

Vaevictis
9/3/2007, 02:50 PM
Cell Phones: YOU CAN HEAR CONVERSATIONS WITH A SCANNER ON ANALOG, you can't on digital.

This has nothing to do with whether the signal is analog or digital.


Digital provides a better signal and no static.

Instead, you get dropped packets and ISI. It's a push.

slickdawg
9/3/2007, 03:11 PM
This has nothing to do with whether the signal is analog or digital.



Instead, you get dropped packets and ISI. It's a push.

Well, I didn't want to get into CDMA vs TDMA vs GSM, that's more than most people ever want to know.

Vaevictis
9/3/2007, 03:30 PM
Well, I didn't want to get into CDMA vs TDMA vs GSM, that's more than most people ever want to know.

Yeah, I'm just saying it's just not as simple as you made it out to be. They both have problems with losses and noise -- that's just a fact of using a mobile wireless channel. It's just that with analog, you "hear" the problems as noise, and with digital you (typically) "hear" the problems as stuttering and gaps.

And you can make it so that you can't just pick up an analog signal with a scanner, it's just easier to do with digital.

(which is pretty much how it all goes -- digital is easier and cheaper, and that's why it's "better.")

Frozen Sooner
9/3/2007, 03:38 PM
Your sister is easier and cheaper.

;)

Rogue
9/3/2007, 03:58 PM
Thanks for the responses. I knew this was over my head. Ask what time it is, you tell my how to build a watch and haggle about the definition of "time." ;)

So, if it's cheaper, why is it that cell phone prices seem to have more than kept up with inflation? Maybe it's subjective, but I haven't bought a $50 phone that gets good reception out here in the boonies in 4 years. Sure, I get cute pictures, cameras, texting, and other crap on my phone that I never use, but primarily it's a phone and the last 3 of them I've had were all teh succ as far as being a phone goes. It's like buying a new fangled car that has a kickass pop-up tent in the back. Great tent, crappy car.

Easier? how?
Cheaper? not for me
Better? so far, not so much

Maybe I don't understand the whole thing about "bandwidth." Why is this an issue. Our IT folks at work are always griping about server space. I looked into it, server space is cheap cheap cheap (probably because of the high fallutin' digital technology). Can't we just magic some more bandwidth?


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sooneron
9/3/2007, 04:27 PM
Digital, without exception.

TV: Less bandwidth, better picture.


Not necessarily. Ever watch an action scene with camera movement following action? it sucks- pixelation crap. With a static talking head shot, it looks better, but motion is a bitch for digital.

Frozen Sooner
9/3/2007, 04:30 PM
Not necessarily. Ever watch an action scene with camera movement following action? it sucks- pixelation crap. With a static talking head shot, it looks better, but motion is a bitch for digital.

That's a bandwidth, compression, and display issue, not a digital issue.

Cable and Satellite HDTV signals are compressed all to Hell.

By way of comparison, watch an action scene off a BD on a 1080p24 compliant display and look for pixelization.

sooneron
9/3/2007, 04:44 PM
That's a bandwidth, compression, and display issue, not a digital issue.

Cable and Satellite HDTV signals are compressed all to Hell.

By way of comparison, watch an action scene off a BD on a 1080p24 compliant display and look for pixelization.
How are bandwidth and compression not digital issues?

And it aint my display that's the issue.

Frozen Sooner
9/3/2007, 04:50 PM
How are bandwidth and compression not digital issues?

And it aint my display that's the issue.

Because they aren't issues inherent to digital. For example, you'd get some pretty big bandwidth issues attempting to pass an analog 1080p signal farther than about 10 feet. Compression artifacting is a compression issue-it can be mitigated with a better algorithm or a lossless algorithm. Just because a signal is digital doesn't mean that it's going to necessarily have artifacting.

And I'm not impugning your display. For some people, artifacting is a result of their display having a crap A/D converter, slow response time, or other problem.

Vaevictis
9/3/2007, 06:31 PM
So, if it's cheaper, why is it that cell phone prices seem to have more than kept up with inflation?

Because instead of keeping the features the same and dropping the prices, they keep the price the same and add features.


Easier? how?

Easier to implement. A lot of the analog parts are really hard to shrink down to smaller than phone-brick size. And you can't do a firmware update on analog parts.


Cheaper? not for me

Yeah, actually it is. It costs more to run an analog infrastructure than a digital one, and you'd end up paying for the difference (plus a fat profit margin).


Better? so far, not so much

At any given price point, digital is going to be superior on the balance in terms of reliability, maximum subscribers and features.


Maybe I don't understand the whole thing about "bandwidth." Why is this an issue. Our IT folks at work are always griping about server space. I looked into it, server space is cheap cheap cheap (probably because of the high fallutin' digital technology). Can't we just magic some more bandwidth?

That would be nice, but you can't just magic up more wireless bandwidth. Server space is very easy comparitively.

For one, you don't have to hassle with the FCC to magic up more server space; you do for more frequency band. For another, the higher up the frequency spectrum you go the more power you need to use to transmit the same distance, and it's not a linear progression, it's usually modeled at at least a second order progression, and that's for straight LOS, which usually isn't the case. For yet another, cranking out chips (analog or digital) that run in the tens of gigahertz/terahertz range ain't exactly cheap.

OUinFLA
9/3/2007, 07:12 PM
nerds