Creating new CDs from old CD tracks -- how not to lose quality? (OS X)

April 20, 2008 11:20 AM

How do I create my own CDs from existing CD tracks, without losing quality on OS X? It seems iTunes will let me rip to WAV but will it then burn back to CD in the same quality? I don't want to go through any encoding/decoding stage.
posted by deeper red to computers & internet (11 comments total)

WAVs are a lossless format. If you rip to wav, and then burn in iTunes, you won't lose any quality.
posted by chrisamiller at 11:39 AM on April 20

Well, okay, i should clarify. WAVs can be compressed, but it's very rare. Most, including iTunes, will use the PCM lossless format.
posted by chrisamiller at 11:43 AM on April 20

Using the Apple Lossless Encoder to import tracks will also give you lossless quality, with significantly less disk space than WAV. It's under Preferences > Advanced > Importing > Import Using:
posted by designbot at 12:15 PM on April 20

Well, okay, i should clarify. WAVs can be compressed, but it's very rare. Most, including iTunes, will use the PCM lossless format.

This I know, but can I be sure that iTunes won't do some weird transcoding stage? This is Apple, where the magic is hidden.
posted by deeper red at 12:39 PM on April 20

Using the Apple Lossless Encoder to import tracks will also give you lossless quality, with significantly less disk space than WAV.

But will conversion to WAV for burning to CD still be lossless? It's the conversion that's the key issue here.
posted by deeper red at 12:40 PM on April 20

You can also drag the songs off the CD in the Finder, create a playlist, and drag the AIFF files from the Finder to the playlist, then burn the playlist to a CDR.
posted by tachikaze at 12:49 PM on April 20

But will conversion to WAV for burning to CD still be lossless? It's the conversion that's the key issue here.

CD's don't contain WAV files; they contain raw digital audio. When you rip it to your computer as WAV or AIFF, that raw data stays the same; it just gets wrapped a little differently. When you burn it back to a CD, iTunes strips that wrapping and burns the raw data again.

Apple Lossless compresses that raw data, like a ZIP file. When it gets uncompressed and burned again, though, it should be bit-for-bit identical to the original rip. Hence the term Lossless.
posted by designbot at 1:49 PM on April 20

CD's don't contain WAV files; they contain raw digital audio.

But WAV files encoded at the standard 16-bit 48KHz ARE raw digital audio.
posted by deeper red at 2:24 PM on April 20

CDs are encoded using AIFF. Use the "Get Info" command in iTunes (in the File Menu) to check the encoding settings for a CD track. I think the settings are for AIFF 44.1K or something similar (I seem to remember that the computer's default is 48K, but CD default is 44.1K). Then, tell iTunes to import using the exact same settings. That way iTunes won't convert anything, it will just copy the data.
posted by reeddavid at 3:17 PM on April 20

But WAV files encoded at the standard 16-bit 48KHz ARE raw digital audio.

Not exactly. It's the same information, just rejigged and presented in a different way for a computer to understand it. Kinda like how WAVs and AIFFs are (usually) both essentially "raw digital audio" but are different formats.

Anyway, in all practical terms you're a-ok to go ahead.
posted by Magnakai at 4:50 PM on April 20

All CD audio is stereo, 16-bit, 44.1kHz Pulse Code Modulation. WAV and AIFF and Apple Lossless maintain this quality. When burning, iTunes maintains this quality.
posted by Monochrome at 8:52 PM on April 20