On the ringing path of Sony X 10 alarm.

Ringtones require you to create several folders on the sd card (which can be operated on the computer).

Alert (folder name) Here is an alert.

Notice, this is the SMS ringtone.

The bell, this is the bell.

These three folders can be built in the root directory of sd card, or in your customized directory. As long as the names of these directories are correct, put your favorite ringtones in the folder, so you can see them when you choose ringtones again. If you don't understand anything, please ask me. I'm also using X 10. Have a nice day!