Bit rate refers to the rate that data is flowing in bits per second. The greater the bit rate, the more data is played back every second.
Kbps means kilobits per second—the higher the number, the better the sound and the more space a music file will consume on your computer or iPod. Conversely, the lower the number, the lower quality of audio will be and the less file space you’ll take up. Most often, files are compressed to 128 kbps, 160 kbps or 192 kbps. The standard bit rate default in iTunes is 128 kbps, but you can customize your rate to go as high as 320 kbps (you make your bit rate selection when choosing your compression format).
To give you an example of how bit rates works, a 4-minute song requires about 3.7 MB of iPod/hard disk space at 128 kbps and about 4.7 MB at 160 kbps. If you go to 192 kbps, you’d have a 5.6 MB file, and file sizes increase accordingly each time you move to a higher bit rate.
You may find that your music sounds fine at the 128 kbps rate, but if you want true audiophile-quality sound to fully appreciate your Klipsch headphones, you should go to a 192 kbps or 256 kbps rate. Bit rate and file size don’t usually pose a problem unless you have tons of music and want to fit it all on your iPod. That’s when you have to make a choice: better sound quality and fewer songs, or lower sound quality and more songs.