It seems to me that it is impossible to change the default alarm tone. Does anyone know if it's possible to do that?
I am using Sony Xperia Z2, if that matters.
Oddly enough, Android doesn't provide (as of the time of writing) a way to change the default alarm tone: if you navigate to Settings > Sound & notification, you can pick "Alarm volume", "Phone ringtone" and even "Default notification ringtone", but there's nothing about an "Default alarm ringtone".
The solution that worked for me came from this post. It requires using the ES File Explorer (install it if you don't have it yet, you can remove it afterwards). The steps below are to pick one of the existing alarm sounds as the default one, but can be used for any sound in your SD card. Here's what you do:
After doing this, all applications that use alarms will use the chosen sound if they're configured to use the system default. The stock clock app will also use this.
You can do this with zedge. When you download a notification sound and choose the "set" option, it will give you a choice of setting it as the main ringtone, the default alarm, and two other options I can't remember right now.
Once you move your song or ringtone into the file you have created and you click on it and file explorer if you push the three dots on the top right it'll say set ringtone push that and it'll give you the three options shown in the picture!
It is hidden down the alarm options. You must slide up to see the rest of options configuration for each alarm.
Open a file manager, choose the sound file you want, and move the file to the 'alarms' folder.
Once there it will show up in both sections of the clock app under," Alarm sound:" "Alarm Tone," and "Music," but you must select it! It will not self-add. Tap either one and scroll to it; tap on its name, (not on the right which is play only), tap Save.
To have a more or less permanent Clock/Alarm of this sound: tap +(add), select the sound, and set the time/date for anything, >Save. Now simply use that alarm by resetting the time/date, instead of crafting a new one, and the alarm sound will follow at that setting.
From BeOhBe
http://userguide.sonymobile.com/referrer.php?region=global-en&product=xperia-z2#!Alarm-clock.html