Help!! System ready sound

So I am Trying to personalize my laptop.... I am using ubuntu 13.04, I tried to change the system ready drums "conga" sound. this is what I did.
1. convert my own .mp3 file to a .ogg file and name it system-ready.ogg.
2. I opened /usr/share/sounds/ubuntu/stereo as root and replaced the file that was there with mine, but the sound is not playing for system ready.
I looked into trash to restore the other file but I cannot find it anymore, because I read later that this was just linked to dialog-question.ogg, so I guess the system ready sound commando is just not being told to the computer.
How do I configure so I can have my computer play the system-ready.ogg file I put in the folder,
I have play system ready enabled in dcong-editor com.canonical.unity-greeter.

thanks.