[Horizons]

I obviously don't understand bit rates on ripped audio data files.

I rip all my CDs in iTunes to Apple lossless with error correction on. They all show up in iTunes as 44 KHz/16-bit which makes sense but they all seem to have very different bit rates. Why is this?

[ctviggen]

I'd assume because they're taking the compressed data value and dividing it by time to get a "data rate".  For instance, if one song is compressed to half of its size, it'll "appear" to have a 22khz data rate.  If another song is compressed to 3/4 of its size, it's appear to have a 33khz data rate.  Those are only appearances, as the true data rate put to the sound card (or to the DAC on the soundcard) will be 44.1khz.  Each song will not compress to the same size, in terms of percentage from raw data.

[philipp]

Um, no ctviggen. I'm afraid that's not what Horizons is seeing. The 44 khz/16-bit part concerns the sample rate of the file, the bit rate concerns the size of the file.

If you ripped the files off of a CD as WAV or AIFF files, they would always have a 1411 kbps bit rate. When you compress them, that bit rate drops but has no effect on the original sample rate.

It is possible to use sound editing software to reduce the sample rate, thus reducing file size. That's the way people used to shrink file sizes when the only way to share sound files online was in WAV format. Fortunately, that's in the past and now we much better options like MP3, AAC, Ogg, FLAC, Apple Lossless, etc.

Horizons, Apple Lossless uses a variable bit rate encoder to decrease file size. Dense, complex sounds result in less compression and higher bit rates. None of this results in actual data loss. The song remains the same as it is on the CD.

[Folsom]

Philipp is right, sorry ctviggen but the lossless ones never change the sample rate.