Theory - the inherent problem in digital music

[Raven 10+ year member]

Ok, it's midnight and here I am thinking again. It's just wrong. Anyway, here's the theory.

Digital music is stored as a sequence of numbers placed at predetermined intervals. Basically a series of X,Y coordinates, one every 44 thousandth of a second most of the time. Like a line of dots.

Dots create jagged edges.

Here's an image of a rough 4.4khz wave, which I made originally using the vector tool in the GIMP, then remade using the polygon tool at a sampling rate of 44khz to simulate being stored on a CD . This is accurate to the best of my knowledge. 4.4khz is an incredibly common frequency in music. It gets better as you lower the frequency, and worse as you raise the frequency. It gets ugly really quick.

Click to read more...

 

[JimJ 5,000+ posts]

I'm not very fluent in digital sampling technology...I can only go by what my ears tell me...

 

[DBfan187 5,000+ posts]

10100101100

I can't hear that!

 

[squeak9798 5,000+ posts]

Remember; there is a difference between what's measureable, and what's audible....if that's what you were getting at.

 

[Raven 10+ year member]

Yes, I understand that. It's why I said theory.

 

[analogkid]

thats why the purists prefer records. it is said that the differences between cd and record can be heard. but with the higher quality cd players around and new teconology the gap is decreasing.

 

[Raven 10+ year member]

It's not "new" technology, more of improving existing technology.

Upping the sampling rate of given music is the next big step in digital music format, IMO. Naturally. the "experts" say it's because it allows the stored song to play higher frequencies. I think it is because it improves existing waves under 20khz. Take that wave I traced, and use 40 points instead of 20, and you're at 88khz. 80 points for 176khz. You'll notice with 80 points, it's pretty **** smooth.

 

[Raven 10+ year member]

CD > Record
CDs have a sample rate of 44,100,000 Hz ...

44100000/4400 = 10022.72727 dots per wavelength

Jmac, that's a 44.1 megahertz sampling rate. My sound card can't handle over 48khz. Where does this info come from?

 

[Raven 10+ year member]

Threw me for a loop there, Jmac. =)

 

[T3mpest 10+ year member]

the difference between what's audible and what a machine can pick up is really big. A TV set is nothing more than thousands of colored dots, only 3 colors, yet look how realistic TV looks, even non HD models are photo realistic at all but the closest distances. Think about how small a time 1 second is, then divide that 1000 times, the divide that by 40, for all intents and purposes it's instantaneous. Even light going through a vaccum would have only traveled 22369 ft during that interval. That might seem big, but to put it in perspetive a racecar going 240mph has only traveled

.098 inches approx the width of 14 human hairs, yes WIDTH!

PS.Physics majors at 3 in the morning are scary too

 

[JimJ 5,000+ posts]

http://answers.google.com/answers/threadview?id=375592

 

[Raven 10+ year member]

http://answers.google.com/answers/threadview?id=375592

I stopped reading at "44,100 snapshots in a minute" which is less feasable than Jmac's 44.1 mhz sampling rate.

 

[JimJ 5,000+ posts]

Yeah, that guy later put his e-foot in his e-mouth //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

I don't know. Like I said before, I'm not fluent enough in the digital theory to be able to quantify that side of it, I can only go by what my ears tell me. And they tell me they're rather listen to an LP than a CD.

 

[Spr0ket 10+ year member]

There are some vinyl recording tools available for the purest audiophile. The system records variations in depth from five different angles. The information gathered is stored in hexdecimal form and can make an accurate copy of the LP without a loss in quality of linear data sampling. Not sure where you can find information on it online, but it's something I've read about in a few audiophile mags.

 

[Raven 10+ year member]

I saw that ad in Sound & Vision magazine. $599 for that thing, IIRC. In all truth, I heard later on that people said "it sounded more like a CD than a record". Which would make perfect sense being digitally transferred.