Make the ringtone a less than 30 seconds long .m4r file (it is a renamed m4a file), put it in "Tones" in iTunes, and sync with the phone. Don't forget to enable sync'ing Tones when the phone is connected.
- Figure out the starting and ending time of the sound snippet by looking at the video in youtube.
- Get the youtube URL, i.e. http://youtube.com/watch?v=Rqz_JyAUZyg
- Go to http://www.clipconverter.cc
- Enter the url in the box
- Click on m4a (to only get the audio)
- Click on "Start of video" and "End of video" and fill in the starting and ending time of the clip. The total length must be less than 30 seconds. You can also choose to fill in the ID3 info (arist name, name of song, etc.)
- Click on Download
This step is only necessary if you have an audio file longer than 30 seconds that is not in m4a format.
One way to shorten the file and convert it is via iTunes. (A perhaps easier way is to open the file in QuickTime Player, trim it with Command-T, and export it to iTunes.)
- Open "My Music" in iTunes (the note symbol in the upper left corner)
- Drop the downloaded file into your library.
- Ctrl-click on the file and choose "Get Info"
- Click on "Options"
- Check the "Stop" box and enter '0:30' which means 30 seconds.
- Click OK
- Ctrl-click on the filename again, and chose "Create AAC version"
- Ctrl-click on the new (30 seconds long) file and choose "Show in Finder"
When your file is a 30 seconds (or less) long m4a file, rename it to end with m4r (ringtone).
- Press alt and drag the file onto the desktop (to create a copy)
- Rename it to something that ends with .m4r. It should also have a name different to the original file.
- When asked if you want to change the extension, choose "Use .m4r"
Now you have a 30 second long snipped of the audio in m4r format.
- Go back to iTunes. If you don't see the bell in the upper left corner, click the three dots.
- Click on the bell to choose "Tones"
- I had to disconnect my iphone here for the next step to work. (I had to use a different name on the file than the original file name, or the file ended up in the music library.)
- Drag the m4r file into the Tones window. It should appear in the list.
- Now connect the phone, click on the phone icon, and on Tones in the phone menu. Make sure "Sync Tones" is checked.
- Press "Sync" in the lower right corner of iTunes.
- To choose the new ringtone, open your phone and open "Settings".
- Click on "Sounds"
- Click on "Ringtones"
- Choose your new ringtone. It should be on top of the list of ringtones.
beeep beeep