You download music. At random, you download a song that sounds "wrong" somehow, or just utterly like crap. You rip your CDs and suddenly find your hard drive has filled up faster than a supermodel at a fast food resturant. You wonder if those subscription music services or pay download sites are worth it.
What is Compression?
The thing that makes MP3 technology so popular is its ability to fit high quality sound into a rather small file by compressing it. Compression involves squeezing a file down with as little loss to quality as possible, using mathematic algorithms and special computer magic dust to make it work. In other words, it doesn't really matter HOW it works for must of us, just that it does.
What you do need to know is the numbers. Generally, the higher the number in kbps or kb for a music file, the better it is going to sound. Also, the higher this number, the larger the file will be. The general range for MP3 files is between 320 Kbps and 8 kbps. 320 will give you just about max quality that only a true audio snob would scoff at. (And since your ears are more likely than not damaged due to years of loud music, 320 will count as perfect to you.) 8 kbits is a really small file, but it sounds like crap. Literally. If you could somehow convert crap into audio form, 8kbit music would be it. (N'Sync at 8kbits would be considered diarrhea.)
While you consider that lovely image, glance over this table of common compressions for reference:
So What Do I Do?
Windows Media Player:
When Downloading from Kazaa, etc:
A couple notes: When using a download program, weird numbers that are uncommon usually mean bad quality or a messed up file. Don't go for them. And if you download a file and the number fluctuates randomly, you it's generally okay, but it may be an indication of a bad file. Also, if you are paying for your music, you better demand top quality. Don't get ripped off. 128 in these cases is the bare minimum. But it should be a higher quality.
Right Click the Link and select "Save Target as" to download each clip so you can compare them to each other closely.
Now let's kick it up to a more complex song, then end it with a full out studio song. This next song is Is another SL Recording of the song Phone. It has drums, guitar, bass guitar, and vocals. Notice how much quicker it degrades in quality.
Even then, those songs were recorded using just a regular PC. Studio quality recordings are painstakingly edited to get rid of extraneous noises, accentuate certain instruments at certain times, and generally impress you. The artist(s) paid good money to make things come out just as they wanted (which is why the sudden controversy over music swapping has occured, you can easily duplicate high quality music an infinite amount of times as long as it was compressed correctly the first time.) It'd be a shame to see what would happen if one of these painstakingly crafted pieces of music were put through the same process, eh? Well, people trade music of this quality anyways, and others may even be duped into buying it. So here I've taken a 30 second sample of Maroon 5's "Harder to Breathe," to which the full song can be downloaded for free here at MP3.com.
Now do you believe me? Good. The same degradation you noticed also happens when you drop from 320, to 256, down to 128, but as I said, unless you're a real audio snob, or it's one of your favorite songs with real complex instrumentation, you won't notice unless you turn it way up. The final point is, if you are going to rip your CD collection for computer storage, or for playing on an MP3 player, you want to go for as high quality as possible. Every CD ripping program you have allows you to control the compression rate of the music. (Our tech-man Fraxyl recommends ripping CDs using CDex, a free program.)
Now you know, so stop sharing low quality music, or making your friends listen to a "really cool mix CD" you made of crappy sounding music (at least quality wise. Music taste notwithstanding.)