Oregon 450 Custom Alert for POI's

Hello,

I have a question about the Oregon 450 and custom POI Alerts. I'm have set up a proximity alert for 50 meters as a test for the address across the street. When I cross in to the boundary the alarm does sounds, however it’s not that loud (more like a beep). Is there a way to replace the beep alert with a custom alert? I have tried to use Extra POI Editor to add a custom mp3 alert but nothing sounds when I cross the boundary. Any guidance would be greatly appreciated.

Thanks,
Kris