Uh, it doesn't matter if its imported as a mp3 or m4a file. itunes doesn't encode DRM. DRM is only in files (yes files. Applies to movies/videos too) purchased through itunes. SO it doesn't matter what format its imported.
BTW for those with iphones. I know of a way to crop and convert songs into ringtones free, just using itunes . (the "create ringtones" feature doesn't work ).
1.In itunes, right click the song you want to convert -> get info -> options. 2.Mess with the start/stop timing for the part you want to be your ringtone (doesn't crop the actual file).
3.preview it by just clicking ok and playing the song.
4.Once you have it the way you want it, right click -> "Convert to AAC".
5.find the converted song (I check by right clicking and going to get info again, then summary. it should say AAC in "kind" section), drag it to the desktop. delete the "AAC" one in itunes.
6.The one on the desktop. rename the file from ********.m4a to ********.m4r.
Then just drag and drop in the ringtone section of itunes.
Remember to go back to the original one and changing the start/stop back
*** If you want, let say the whole song (longer than 30sec), itunes won't let you use it as a ringtone... unless you delete the original song from itunes. Then you can add the ringtone. I just move the song somewhere, delete it from itunes, drop the ringtone in, and drop the song back in