Digital Audio: What is the bit rate for an mp3 to produce a high quality sound from an ipod?

BEST GENERAL SETTINGiTunes > Preferences > Import Settings Import Using: AAC Encoder Setting: iTunes Plus (128kbps (mono)/256kbps (stereo), 44.100kHz, VBR, optimized for MMX/SSE2) HIGHEST QUALITY (BUT MUCH LARGER FILES)iTunes > Preferences > Import Settings Import Using: Apple Lossless Encoder Seting: Automatic IN GENERAL Apple Lossless should sound exactly the same as the CD. No MP3 or AAC file is "CD quality" or "Better than CD quality," but depending on what you are playing it back on, you may not be able to hear the difference, and an MP3 or AAC file may sound acceptably good and take up much less space than a WAV or Apple Lossless file. MP3s are more universally playable on different devices and platforms. AAC encoding will sound better than MP3 at the same bit rate. If you are using Apple products exclusively, then it is fine to go with AAC or Apple Lossless formats for your devices. I wouldn't go below 160kbps when encoding music. 128kbps is noticeably inferior, even on average stereo equipment.

Higher bitrates generally mean better... but it's not a simple problem. When you're compressing to MP3, AAC, or other lossy formats, some information is going to be tossed out. The more you toss out, the lower your bitrate, and all things being equal, the more readily you'll hear the difference. Think about it for a second.. you can routinely compress an audio file to 1/10th to 1/15th of the original size and not notice much change. That's pretty amazing, eh... tossing out 90% or more of the information and not noticing a change. The compressor works using what's called a psychoaccoustic model, which, in short, is a model of how your brain processes sound, and this, of what can be tossed out without you noticing much. Now, add into the idea of variable bitrate. It's possible to just apply the same compression to any bit of sound, but there are a couple ways to do this. The more intelligent way is to essentially toss out the same amount of information for each chunk of music, regardless of whether it's dense or sparsely populated. This results in some sections being smaller, others larger. So if you're analyzing a VBR file and seeing 32kb/s or 64kb/s, that's likely an area of less activity.. more data can be thrown out without sacrificing quality. Ultimately, if you want to control the bitrate, you have to set the bitrate, plain and simple. All told, a 256kb/s VBR compression can sound better than a 160kb/s VBR compression with the same CODEC, and it will never sound worse (unless there's a bug in the CODEC). Does this necessarily make a difference to you, listening through the marginal audio pathways of an iPod into what's likely (eg, most folks use) the cheap earphones that come with the iPod? Only you can say that for certain.

For classical music, go with 256 kbs AAC. Or better yet, use Apple lossless compression.