Will a mp3 ringtone work on your iPhone?

here's what to do:

1) go into cyberduck/winscp and SSH to the root directory.

2) then go to /System/Library/Audio/UISounds

3) replace alarm.caf with any other file you have called alarm.caf

.caf means Core Audio file so you probably need to do this part on a Mac

I used Fusion to clip an mp3 file and save it as an aiff. then i opened the aiff with Apple Soundtrack Pro and saved it as a Core Audio file. The whole time I kept the save settings as 16-bit /44100 kHz /1411 kbps bit rate, just like the original. The only thing different about my file is the length and maybe the dB, but it worked.

4) reboot the phone, you must reboot for Core Audio to reload it's files!