Converting to aac

Question

just finished ripping my 700 cd's into itunes using apple lossless (8500 songs = 260 gig)I would like now to convert them to aac to fit on the ipod, is there any harm converting all and leaving everything in the itunes folders, i do want to keep the apple lossless to make compilations cd's (I bought a 500 gig drive just for this purpose so i have plenty of space left for the aac's)

Answer 1

I also found this note on macosxhints.com:
http://www.macosxhints.com/article.php?story=20061025105820390
*Smart playlists for lossless and AAC files in iTunes and iPod*
*Tue, Oct 31 '06 at 7:30AM PST • Submitted by reg*
I have ripped all my CDs in Apple Lossless format, so I won't have to rerip them when a new or better codec comes along. I have found many ideas on how to copy all songs into a second iTunes library in and then convert all songs in the copied library to a lossy format such as 192 kbps AAC.
However, with smart playlists, it is possible to create a single iTunes library that is still fairly convenient to use, and that contains both the lossless versions for listening on the big home stereo, and the AAC versions for syncing to the iPod. Here is the setup:
Create the following two playlists:
"Lossless": match all conditions - Kind contains Apple & Kind contains Lossless
"AAC-192": match all conditions - Kind contains AAC & Bit Rate is 192
Now the two main playlists for use on iTunes and the iPod:
"All-Mac": PlayList is not AAC-192
"All-iPod": PlayList is not Lossless
These two playlists are defined by excluding the unwanted versions, so other MP3s and purchased songs will appear in both playlists. (If you want to use the same scheme, but rip to a different bit rate, such as 128 kbps, you will need to set up the corresponding playlist containing the rule "kind does not contain protected".)
Once you have set up these playlists, "Lossless" will contain all your CD-ripped music. If you now set the "Importing" settings in the Advanced tab of iTunes' preferences to AAC and 192 kbps, you can select the Lossless playlist, select all songs, and choose "Convert selection to AAC" in the Advanced menu to create the AAC versions. Once this possibly lengthy process is finished (it can take a few hours, or more, depending on the size of your library), you'll find the iPod versions of all your lossless songs in the "AAC-192" playlist.
Now you have to set up your iPod to only sync the "All-iPod" playlist, and you're reading to listen to your music on the move.
If you now create additional smart playlists, you will have to include a condition "playlist is All-Mac" if the playlist is intended for use in iTunes, or "playlist is All-iPod" if the playlist is intended for use on the iPod. I have started to prefix all my iPod playlists with "i-" to easily identify them.
There are some caveats:
You have to manually keep the AAC versions in sync with your lossless versions: if you add to or modify your Lossless library, you have to manually convert the files to create corresponding AAC versions.
Also, play counts, skip counts, last played times and ratings of lossless and AAC songs are separate, which means you'll have different information for the two different versions of a same song, but this still a fairly straightforward way to manage these two types of files, and, in my opinion, better than using completely separate libraries.
[kirkmc adds: Interestingly, I have an article coming in the December issue of Macworld about this very question. I discuss the process of ripping to lossless to use files as "archives", for the same reason as reg, that is to be able to re-rip to any format at a later date. In my article, however, I discuss using two libraries for the different types of files; since iTunes 7 has built-in multiple library support, and because there are third-party solutions such as Doug Adams' iTunes Library Manager, I prefer the multiple-library solution. But reg's presentation here of using smart playlists is a very good way to do the same thing with a single library. Just make sure you have the necessary disk space!]